Teardown - Hitachi V1065

[grumpydoc]

I happened across another Hitachi V1065 recently so thought I'd take a few pics this time as I checked it out.

Hitachi made several 'scopes and the V1065 is one of a series of very similar instruments made in the mid-late 80's. It's a 100MHz bandwidth analogue 'scope with cursor readout. They're actually very nice 'scopes to use although there is a bit of "one knob does everything" going off with some of the settings. The tubes are very nice and have an utterly pin-sharp trace. They are also a nice 'scope should you need to do any DIY fault finding as they are almost completely standard parts (except the custom CPU).

Manual including schematics at http://www.wild-pc.co.uk/docs/Hitachi-V-1585-65-60-V-695-OM-Schematics-English.pdf

There was a thread recently on what constitutes a teardown - this is more a take-apart than teardown but I still find it useful to see how something goes together. As it happens there was no great problem with the 'scope - the small selector switch used to control the function of the "variables" knob was sticky and didn't return cleanly to the centre position - getting the front panel PCB out to get at it to clean/lubricate it needs pretty much the whole 'scope taking apart.

In fact this is really a tear-up as I'd got the whole thing apart before I thought of taking any photos - so they were done in reverse order as I put it back together.

Overall view (click on pictures for high res version).


Whilst obviously not as small or lightweight as a modern DSO these are very compact. Military green seems to be the only colour though

Taking a peek inside


The top board is the PSU including all the high voltage sections - there is some protection for these but I don't think I'd want to accidentally put my hand on here with the thing powered up. The final X amp and Z-mod circuits are here as well.

The PSU board has a hinge mechanism which allows it to swing up towards the front of the 'scope. I'm not sure if the intent was that he instrument could be run powered up like that as it's hard to get to the CPU/X board to fault find but if so then it's a bit of a fail. The two mains input leads and another inter-board connect are way too short to allow the PSU board to swing up.

I find it's easier to swing the PSU board out to the side. In fact the 'scope can be powered up like that if the mains input to the board is extended (and one is very careful with the position of the board - lying the board flat on the bench with the 'scope on its side works best).

The back of the PSU board has nicely labelled points to check the supply voltages.


Swinging the PSU out of the way shows the next board down which is the CPU/horizontal board.


Construction is a mix of SMT and through hole. Most (but not all) of the passives are SMT with the ICs (mostly 74LSTTL on the CPU board) in DIP packages.

Flipping the whole thing over shows the solder side of the vertical board and the delay line - which looks huge compared with the ones in the Tek 2200 series 'scopes.


You can just see the yellow trimpots for calibration on the horizontal board - all in the same area of the board. In fact you can get at these by taking off just the bottom of the case.

The vertical calibration points are all on the component side of the board but with holes through to allow access. They are all nicely marked on the solder mask as well.


Round the side is the final Y amp. You can only really see the solder side of this board as it's close to the end of the CRT. Again the functions for all of the variable caps and resistors is marked on the silk screen.


Trying to get the CPU board out is made harder by the fact that not all of the interconnects are long enough - it gets just far enough out to start to disconnect everything


Once a few are unhooked it's possible to swing the board up. Almost all of the header plugs are different sizes so it's fairly easy to make sure everything is going to the right place on reassembly.


Finally we have the boards out and the chassis is looking a bit bare but we can get at the gummed up switch. Strictly speaking I didn't need to take the plate off which forms the visible front panel but it badly needed a clean.


The offending item is the toggle switch just above the array of LEDs - underneath the paddle there's a fairly normal centre biased toggle. A quick squirt of switch cleaner and a bit of light lubrication and it's as good as new.


The CPU is an NEC D78C14G micro-controller. Odd 64 pin "quad" DIP package which was briefly used in the late 80's before (thankfully) disappearing. It appears to be a bit Z80ish but doesn't have compatible machine code. Date codes on the ICs suggest a mid 1988 build date for the 'scope as a whole.


Datasheet for the CPU at http://www.wild-pc.co.uk/idocs/NEC_D78C14G.pdf

Looking down at the top of the Y board we can see the readout boards which tell the CPU which attenuation has been set, otherwise there isn't actually much to see on this board.


Even with the screening removed the board is fairly boring.


Finally a shot showing how I swung the PSU board out of the way. The high voltage side is screened off (it almost touches the CPU board when everything is installed.


The screening mostly hides the two transformers.


The CRT anode potential is 15kV. Slightly unusually this is generated straight from the HV transformer - there is no multiplier (at least if the schematic is to be believed).

Finally back together and running


For a notionally 100MHz 'scope it does rather well - though the frequency response is a bit odd. It's about 2-2.5dB down at 100MHz but then drops slowly to not quite 3dB down at 124MHz before increasing a bit for a few MHz, then falling again and finally hitting -3dB about 150MHz, then tailing off as expected. Max stable trigger is around 150MHZ (although it's a bit tricky to get a clear display at this frequency).

Hope you enjoyed the teardown folks

[true]

Thanks for the photos and description.

These scopes sometimes come up as a deal (they don't say "Tek" on them so nobody wants them) - I have two myself, a 1065 and 1065A (has a frequency counter).

I did a bit of a teardown myself to try to fix some audible high-pitched noise in the 1065A...even swapped the PSU board and CRT between the scopes (the 'A was pretty well used but the non-A was near new) but it didn't really make a difference. Oh well, they work... I was wondering if I can unlock freq mode on the 1065 non-A though? Didn't care enough to proceed with that one...

That switch and the timebase buttons were gummed up in both of mine. (Timebase would work, but Auto would not work reliably until I cleaned the buttons.)

The link to the CPU datasheet is 404.

[grumpydoc]

Thanks for the photos and description.

These scopes sometimes come up as a deal (they don't say "Tek" on them so nobody wants them) - I have two myself, a 1065 and 1065A (has a frequency counter).

Thought it was the 1065C which had the counter.

I was wondering if I can unlock freq mode on the 1065 non-A though?

There's an extra board which goes in the "C" so it's probably not just a question of "unlocking" the functionality.

That switch and the timebase buttons were gummed up in both of mine. (Timebase would work, but Auto would not work reliably until I cleaned the buttons.)

The attenuator switches can get gummed up as well - the ones here wern't too bad so I left them.

The link to the CPU datasheet is 404.

Fixed.

[true]

Thought it was the 1065C which had the counter.

Not aware of 1065C... not many search results for that. The 1065A certainly has the frequency counter. It works like any other frequency counter. Not a whole lot of resolution but in my brief tests a while back it was quite accurate and pretty quick. Will have to test again...

I do remember that the counter is tied to the trigger.

There's an extra board which goes in the "C" so it's probably not just a question of "unlocking" the functionality.

There is no extra board that I see in my 'A or even additional chips which is why I was thinking it may be something unlockable but I didn't look very hard. Or maybe it's just different firmware...

The attenuator switches can get gummed up as well - the ones here wern't too bad so I left them.

Yeah, but that's true on any scope really My 'A knobs are pretty well shot - they work but they don't snap into place very well. My non-A, after cleaning, feels like new.

[grumpydoc]

Not aware of 1065C... not many search results for that.

It's referenced in the manual and the only difference seems to be the frequency counter. "C"=Counter, presumably. I've never actually seen one.

I suppose the "A" was a revision and they just threw the counter in and only had one model.

In the schematic an extra ROM board is mentioned which is only present in the 1065C, I presumed there was a bit of extra firmware for the frequency counter, plue perhaps some pre-scaling before feeding the signal into one of the counter/timer inputs. The schematic isn't all that clear - after a 5 minute look I'm not sure whether they could have implemented the counter that way - I need a bit longer staring at the diagram.

I'm not sure why that makes your 1065 and 1065A look the same - I'd ask for photos of the CPU boards but they're not exactly easy to get out.

Do you know if there's a service manual anywhere for the "A"?

I do remember that the counter is tied to the trigger.

Yes.

[grumpydoc]

OK have done some digging.

Not sure whether you had this anyway but I found a service manual covering the V1065A which can be downloaded here

This lists the variants of the 100MHz 'scope as V1065A and V1060, the "V1065A" having cursors and frequency counter and the V1060 having neither.

The manual I originally had (and posted a link to) covers the V1065, V1065C and V1060. As above the V1060 has neither cursor readout or frequency counter, the V1065 has cursors and the V1065C has both.

Unfortunately there is no date information from which to work out which is the newer of the two service manuals.

It would appear that the V1065 and V1065A are in two different series of 'scope - which would suggest there is no "simple upgrade" path between the two. In the 1065C variant there is an extra board - "ROM PG CKT" - which carries a 16K (EP)ROM and some address latches.

There are various links (R2113, R2114 and R2171-76) on the CPU board which tells the firmware which 'scope it is installed in, for the 1065/1065A/1065C R2113&2114 are the same (both open) and the others are set as follows:

	1065	1065A	1065C
R2171	0	0	0
R2172	open	open	open
R2173	0	0	0
R2174	open	open	open
R2175	open	0	0
R2176	0	open	open?

The "open?" is because the schematic actually says "*" which I'm presuming to mean open given the 1065A values.

So, it's possible that if you swap R2175 and R2176 (but don't have both shorted as that will short the 5V rail) a 1065 will think it's a 1065C - however I think it's quite likely that it will then try to read some code from the extra ROM board - if this isn't present than that is likely to end badly.

If you fancy giving it a try let us know what happens.

[true]

Finally got some time to hack on this. Sorry it took a month.

I couldn't find anything telling me where these resistors were on the board, since there are no markings on the board and the PDFs didn't show the positions for most passives (or I am blind) so I looked for groups of 0-ohm jumpers. Hitachi used green ones so they were easy to find. I opened the 1065A and compared, noticed a jumper in a different position, so I changed that on the 1065.

IT WORKED! I now have a frequency counter on the 1065 non-A. It's the 4th option of the cursor mode. Since you have a non-A, I will describe where it is:

Take off the cover, and move the PSU board slightly out of the way - up and over without disconnecting cables is fine. With the front of the scope facing you, on top of IC2161 silkscreen you will see pads for 2 resistors (one populated) and below that pads for 3 components (a cap and two resistors). On the 1065, on the line of pads with the cap, the 0-ohm jumper is on the outside... it goes [CAP] [empty] [0-ohm] - move the 0-ohm over into the empty position. So it should be [CAP] [0-ohm] [empty] - this will enable the frequency counter.

As for cal, it's close enough for any sort of work I might imagine I would do with this. 10MHz showed 9.992, above that it started getting worse (59.94 at 60MHz), but below 1MHz was really spot on. (The 1065A is basically spot on until 100MHz, as high as I tested it). It's probably just a calibration thing.

Thanks for investigating this.

---

Actually I edited your board photo; here's what needs to be done.

[grumpydoc]

Finally got some time to hack on this. Sorry it took a month.

....

IT WORKED! I

Wow  that's useful to know. Thanks for trying it and for the update.

Thanks for investigating this.

No problem.

Actually I've now sold the 1065 and it's on its way to a new owner but picked up four V1565's to play with 

These are AFAICS the same 'scope but white and with the frequency counter enabled, unfortunately one had a mangled BNC on channel 2 so I'm just in the process of replacing it. Not the easiest job since the whole 'scope has to come apart to get the bottom vertical board out.

[algorath]

kewl teardown vintage goodness

[true]

Actually I've now sold the 1065 and it's on its way to a new owner but picked up four V1565's to play with 

These are AFAICS the same 'scope but white and with the frequency counter enabled

1565 is basically exactly a 1065A with a wider voltage input power supply and different colored plastics. I wouldn't mind one because every 1065 I've seen is beat up...maybe people took better care of 1565s? (though judging by "mangled BNC" maybe not)

[grumpydoc]

I wouldn't mind one because every 1065 I've seen is beat up

The three I've had (a 665 and two 1065) have been OK and not needed much more than a decent clean up. The 665 was sold as "no readout" but it just turned out that the grid bias had been set so as to make it impossible (or nearly so) to get the readout to show.

Cosmetically the only real problem was that the 665 and the recent 1065 had an almost identical chip out of the back of the front plastic bezel in the to right corner.



The couple that are on ebay at the moment do look a bit beat-up I admit, one with very yellowed knobs as well. In fact I have a 1060 which I'm now resigned to being a parts 'scope as the HT transformer is missing which has fairly yellowed knobs. The two I sold and the 1565's are perfect. That said the 1565's are newer  - probably around 2001-2002. I can't decipher the date codes on the Hitachi TTL and there are very few non-Hitachi ICs in it. A couple have "00" date codes and one could have an "02" data code.

As 'scopes go I like them - they have nice CRTs. You can get an absolutely pin sharp trace out of them.

[true]

Cosmetically the only real problem was that the 665 and the recent 1065 had an almost identical chip out of the back of the front plastic bezel in the to right corner.

MINE HAVE THAT CHIP TOO Only on the right side. Wonder why that is.

Every 665/1065/1565 I have seen in person has been in terrible shape though...but most also seemed heavily used, not bench queens like some Teks I own...

As 'scopes go I like them - they have nice CRTs. You can get an absolutely pin sharp trace out of them.

Agreed.

[grumpydoc]

(though judging by "mangled BNC" maybe not)

Well, it was definitely mangled


As usual click on the pictures for a larger version.

Actually, as I had to get the Y board out here are some more photos - of the 1565 but you wouldn't really know just looking at the boards. To get the Y board out you have to remove the bezel, knobs, printed face-plate and the retaining nuts on the attenuator switches. It's then possible to pull the board backwards and down (after removing the four screws holding it to the chassis. It's easier to unhook all the inter-board connects if the CPU board has been removed first, i.e it's pretty much strip everything out time.

The BNC's are actually attached to a separate bracket


This is, entertaining to remove - not only  are there 5 screws holding it to the Y board there is copper screening which is soldered to the board as well as the connections from the BNCs themselves.

The above pic shows the bracket with the "new" BNC installed. I was just going to grab one from the parts bin but then discovered that a) the ones I had were slightly shorter (so would look out of place) and b) had the flat surfaces at right angles rather than opposite sides of the thread (so wouldn't fit). So I decided to strip down the 1060 that I have and take one from it.

Looking at the shot above I really wish I'd changed the bracket with all three BNC's because the fact that the one from the old 'scope doesn't quite match escaped me until I'd got everything back together  The reason I didn't was more-or-less because the old BNC needed a polish and a thorough wash out with IPA but, actually, it's come up better looking than the newer ones.

Looking at the Y board now it's out of the 'scope it seems quite simple compared with many 'scopes.


The action is mostly on the reverse and it's basically all SMD - the design is probably late 80's and it's interesting to compare with the Tek 22xx series which were only a couple of years earlier and almost completely through hole.



Finally a shot of the BNCs reunited with the Y input board


You can see the copper shield as well as a separate ground wire. Not sure why both are needed.

At last the 'scope is back in one piece - the frequency meter is good to about 125MHz - after that it gets a bit confused although the 'scope will actually trigger OK up to about 150MHz. I can get on with the calibration now, as well - although the 5ns timing looks OK - 40ns for 5 cycles of 125MHz is spot on.




The donor 'scope isn't looking quite so healthy though


While slightly tedious I'll put it back together tomorrow - that way I know where all the bits are when I need them again.

[anjimoo]

Hi, thanks for this teardown. It's been very helpful so far. I also have this scope and this switch is giving me a lot of trouble. Unfortunately after disassembling it I've had no luck fixing the switch by cleaning it. Whatever I do it's never returning to center, instead snapping hard to the up or down positions. It's also hard/unpredictable to move up or down.

The scope is fine otherwise so I'd love to fix this switch somehow. Maybe I can replace it? It's a "Fujisoku AL2S" apparently. I can't find much of anything about it though . Maybe anyone recommend me a new component that will replace this switch? I'm not that experienced with electronics so I don't know exactly what to look for.

Thanks!

[true]

How did you clean it? I had one that would stick completely - I put switch cleaner in the switch and worked it pretty aggressively... it works pretty well now.

But if it is well and truly broken, you may need to figure out what the pinout of the switch is. It may be necessary to make an adapter board...

Or maybe you could ask grumpydoc to give up the switch from his parts unit?

[anjimoo]

I pretty much drenched the switch in contact cleaner. So far it hasn't changed anything. It just refuses to return to the center unless I delicately maneuver and hold it there.

[true]

Then it is likely broken

If you can determine the pinout I can maybe help find a switch...no time for this myself, but I I looked but didn't find any direct replacements. With a pinout I could spare a few minutes to hunt for a switch.

[anjimoo]

I think I've found out how it's wired. Input is on the middle pin on the left of the switch (the one connected to the resistor) on the back of the board, output is on pins labelled 4, 5 and 6 depending on the state of the switch. It appears to be all continuous. As far as I can tell the other pins on the switch are unused.

Hmm I should've noted which position corresponds to which pin .. But I've currently reassembled it .. I'll pull it apart again tomorrow to check.

[true]

If you can, label your image and I'll see what I can find. If nothing can be found you might need to make an adapter.

[grumpydoc]

Use a switch cleaner which has lubricant

Make sure you have given the ball at the end of the toggle a good squirt - I think that's where they get gunked up.

Work the switch a couple of times until it comes free.

Possibly add a tiny bit of light machine oil (not 3-in-1).

If not and you're in the UK then PM me and we might be able to work something out with regard to a replacement.

[Nidhoeggr]

Hi,

I recently got a Hitachi VC-6045 DSO and I also have the issue with an annoying noise from the PSU board, which true mentioned before. Do you furthermore tried to fix it? It's strange, that you didn't solved it with changing the PSU board. That means the source of the problem is somewhere else?

I located (as far as I could) the sound at the Pulse Amp Transformer T1010 (btw. the schemtatic of the PSU & HV generation board is pretty much the same at the first look in comparison with the V1065) and maybe a bit also comes from the HV transformer, but it's very hard to find the exact spot, where it's coming from.

The supply voltages are fine and the DSO itself work brilliant too, but the noise drives me crazy when I measure over longer periods.

If you guys have any approaches to solve this, I would be very thankfully.

Greetings
Philipp


PS: Sorry for the bad english, I'm from germany

[true]

I never figured out the high freq noise issue, as the 1065 now has a freq counter and I'll probably get rid of the 1065A.

This said, I can't find a way to calibrate the frequency counter at all. Don't see anything to adjust on the board that might be related, nor do I see anything in the service manual / schematics... maybe it's some matched components somewhere, sigh... the values do remain pretty close to constant between power-ups and length of time powered up, so maybe I can hack something in somewhere...

[grumpydoc]

This said, I can't find a way to calibrate the frequency counter at all.

No, I don't think that there is. Presumably it relies on the CPU clock  which is probably fine given the resolution is only 4 digits.

[Hydrawerk]

I found a similar scope at school. https://plus.google.com/photos/106264218831814439783/albums/5844454688694290849

[true]

This said, I can't find a way to calibrate the frequency counter at all.

No, I don't think that there is. Presumably it relies on the CPU clock  which is probably fine given the resolution is only 4 digits.

From what I can see in the circuit description, it depends on the trigger circuit, not the CPU. I am a decent amount off, not just a few digits.

[grumpydoc]

From what I can see in the circuit description, it depends on the trigger circuit, not the CPU. I am a decent amount off, not just a few digits.

I've just had a look, not really paid attention to that part of the circuit before.

The trigger circuit is the logical place to start as you obviously want to clean up the input signal to a pulse train to count.

If you look the trigger pulses are fed from the top of R655 (waveform 4 top right of sheet 4 of the circuit diagram) to IC2170 which is an 74AS74 configured to give a /4 frequency division (bottom left of sheet 5). From there it is passed to IC2171, a 74LS393 dual 4-bit counter where a further /32 frequency division takes place. After that it is fed to the PC5 input of the CPU via input selector IC2161 (bottom left of sheet 8 now).

If your frequency counter is off I'd check the CPU clock frequency first - there isn't really much to go wrong, just a crystal, two caps and a resistor straight to the CPU but the CPU clock is the only reference for the frequency counter that I can see.

[Flump]

thanks for the look inside grumpydock
lots of good info here.

I wonder if anyone knows if the scope test point on the front of it
can be adjusted as mine reads 1043 measured by the scope  and not 1k,
my multimeter reads 1042 so it is the test point reading high.

[true]

thanks for the look inside grumpydock
lots of good info here.

I wonder if anyone knows if the scope test point on the front of it
can be adjusted as mine reads 1043 measured by the scope  and not 1k,
my multimeter reads 1042 so it is the test point reading high.

It's not meant to be that accurate. If you want it to be, I'm sure you could solder something in to correct it...

[rbm]

I hope that I can ask a question about the sister scope to the 1065, the V-695 (60MHz model).  They share a great deal in common.

I recently purchased one and just received it in the post.  The owner didn't disclose the broken selector switch (S1603 on the schematic); I assume it is broken because it does not select any of the functions reliably. 

My selector switch has no centre detent position (only up and down), and the up / down positions are not-momentary in operation (the switch remains).  From the above text "fairly normal centre biased toggle" and from the schematics, S1603 looks to be a DPDT centre detent, possibly momentary action.  Is this correct or should the up-down positions be non-momentary?

I'll have to tear into the scope to take a look at the front panel circuit.  However, from the pictures posted above, it appears that S1603 is not able to be serviced.  Will I need to desolder and replace this switch completely or can it be salvaged?

Thanks in advance for helping.

[grumpydoc]

My selector switch has no centre detent position (only up and down), and the up / down positions are not-momentary in operation (the switch remains).  From the above text "fairly normal centre biased toggle" and from the schematics, S1603 looks to be a DPDT centre detent, possibly momentary action.  Is this correct or should the up-down positions be non-momentary?

It's a centre-biased DPDT, open contacts in the centre position and not momentary action. From memory it has a mounting for the grey paddle switch which is the one feature that might be difficult if you try to replace it.

However, it is likely that the switch can be salvaged as it sounds exactly like the switch on the scope I took apart. You do need to remove the front panel switch and LED board which means taking out the PSU/HV board and the CPU board - after that there is enough room to wriggle it out. Take the grey plastic paddle off squirt some contact cleaner or IPA into the top of the switch, then work the switch a bit. It will probably start to come free and work correctly. Repeat if necessary and if the contacts are not working try to get some contact cleaner or deoxit or equivalent into the switch itself. Finish with some light oil into the top of the switch (especially if you used IPA to clean - many commercial contact cleaners have a light lubricating oil in them anyway).

[old gregg]

Seems that the switches end up with issues. I've a Hitachi VC-6023 and its push/pull buttons are a gamble everytime I want to use one. I can't pull the button otherwise it doesn't go back to its orginal position, which give an odd reading.

I thought about changing the part (but not references) but maybe a good cleaning could do the trick.

[rbm]

MINE HAVE THAT CHIP TOO Only on the right side. Wonder why that is.

I've got a theory for this.  Mine also have both top corners chipped.  When I took my scope apart for servicing, I noted that the metal cover is captured by the bezel along the top edge and the two sides.  It needs to be slid into place carefully when removing and replacing.

I think if a ham-fisted service tech just slams the cover into place without being gentle with the corners, the corners get chipped.  Afterall its hard metal versus soft plastic.  Obvious which wins out.

[rbm]

My V695 scope has exactly the same problem as anjimoo posted above.  The selector switch is truly broken on the inside and does not function as it should.  It should have a centre resting position with momentary action either up or down.  Unfortunately, mine stays fully up or fully down and has no centre detent.

I've been doing some research to find a replacement.  Here is what I have found out so far.

The original switch is a Fujisoku ALE2S-2M4-10-Z , DPDT paddle switch with the function (ON)-OFF-(ON).  The technical data sheet for the switch can be found at:
http://copal-electronics.info/en/00134/01b64.pdf

Fujisoku was purchased by Nidec Copal Electronics in 2007 and Copal continues to build the switch.  I contacted the Canadian representative for Copal to ask about the availability of this switch.  I heard back that the switch is available through Digikey via the Copal part number above.  It is not listed on the digikey web site nor is the part number searchable.  The downside is that the minimum order  is 50 units (since the factory has to tool-up to make the switch).

Doing more research on Digikey and Newark Electronics web sites, I discovered a very good substitute for the OEM switch.  This is a NKK Switch, part number A28KB-BH-ND.  This switch has the following characteristics:  DPDT, function (ON)-OFF-(ON), snap for paddles, straight with bracket, Grey 14mm paddle X 4mm wide. The paddle is slightly narrower than the Fujisoku, as shown in the drawing below:

However, any space in the switch opening can be taken up by making a flexible sheet to fit tightly up around the handle, and slide up between the front panel and the scope case.  This switch is not stocked at Digikey or Newark. 

I placed an order with Digikey for the switch.  It was an extraordinarily long lead time to get the switch but it finally arrived.

I proceeded to remove the Horizontal control card as described in the first post of this thread.  Once removed, I desoldered the Fujisoku from the card. It was difficult to do. The reason was that the switch has a metal band that is also soldered to the board in addition to the pins.  There was a risk of damaging the board so to ease the risk to the PCB, I clipped the four tabs that fixed the metal band to the board.  I used a solder sucker to disassemble the solder joints and loosen the switch.  Once free of the board, I proceeded to clean up the pads.  I did lift a couple pads because I don't have the proper desoldering equipment; it would be best to use a desoldering station but I didn't have access to one.


You can see the switches compared side by side below.  The NKK obviously has a smaller paddle.  What is also different between the two switches is the action; the NKK is much softer in its action than the Fujisoku.  I think this softness will give the switch a longer service life.



I double checked the contact action on the NKK versus the schematic and verified the orientation of the switch.



I placed it on the board, soldered up and refitted the PCB back into the scope.  The paddle fit through the opening with no problems and doesn't look too bad.  Operation is perfect and the full functionality of the scope restored.



This is a viable, easy fix for those with a broken Hitachi scope.

[anjimoo]

Thanks Robert! Your research is most appreciated. Looking forward to hear if this component is a proper substitute. My scope is usually gathering dust b/c of the switch. Hopefully this'll revive its use

[Rmcka4004]

 :-BROKEi think I've found a replacement sw at digikey. I ordered it today and will share if it works

[mlloyd1]

Robert:

Thanks so much for your VERY informative investigation.
 
My V-665 has this exact problem and I'd like to repair it so my grandson can have this scope when he is ready for one.

However, I think the exact OEM replacement is actually the Fujisoku ALE2G-2M4-10-Z, right? Looks like the  ALE2S-2M4-10-Z is a rocker.

mlloyd1

[rbm]

Hi,

Either model can be equipped with a toggle or rocker actuator.  The difference between the G and S models is that the G has 2.54mm between contact rows and the S has 5.08mm between contact rows.  The S is the correct original designation.

[old gregg]

Hi,

I'd like to change the push/pull in my hitachi VC6023, they're all dirty and the switching isn't done properly anymore (the trigger becomes quite tricky). The service manual gives as references EVH - YK3325B14 (10K push pull). Does anyone know where I can find a replacement or a sibstitute ? (It's annoying to not being able to use the X10 mag)

I googled the refrences with no success.

[Ether]

Hi, is it possible to repeat the frequency mod on a V-1560. Also, is there some way of preserving the holdoff function while getting the frequency counter?

[grumpydoc]

Hi, is it possible to repeat the frequency mod on a V-1560.

Probably - have a look at your CPU board and see if the jumpers correspond to the "no frequency counter" setting. If so swap them.

Also, is there some way of preserving the holdoff function while getting the frequency counter?

Not sure what you mean by preserve?

[Ether]

Thanks for the reply.

IT WORKED! I now have a frequency counter on the 1065 non-A. It's the 4th option of the cursor mode. Since you have a non-A, I will describe where it is:

I was referring to true's post that the frequency counter was the fourth option of the cursor selection and AFAIK, that's to adjust the holdoff.

[grumpydoc]

I was referring to true's post that the frequency counter was the fourth option of the cursor selection and AFAIK, that's to adjust the holdoff.

Ah, see what you mean.

Holdoff isn't affected - the frequency counter is the 4th measurement function - keep on pressing the selector down until you get there

[Ether]

I replaced the zero ohm resistor as according to true's post but I'm not getting the frequency counter. I did try pushing the selector all the way down though so any help would be very appreciated. 

[true]

Did you keep going down? If it doesn't work, maybe there is something else different in the 1565. I don't know. Would need to look at schematic again, and I'd be willing to, but after some serious recent trouble I am in no mindset to be able to.

[Ether]

Thanks for the reply. I did tried holding the switch down and I compared the 1060 board with the 1560. They match perfectly. Is it possible for you to check my picture against what you did and see if I screwed up the positioning? I fixed the solder joint after the picture  was taken so soldering should be fine. Also, pictures of your 1060 with the counter enabled would be nice.

[true]

Don't hold the selector down, keep pressing the selector down.

It will be a while before photos. Had a major burglary. Scope and cameras weren't stolen but other electronics things like parts and my soldering iron were, and the cameras to secure the house (to be installed the evening of the burglary) were stolen too so I am going to be delayed for a while.

[Spork Schivago]

I'm sorry to bring up a dead thread but I have one of these scopes too, Hitachi V-1065A.  The rocker switch was bad as well on mine.  It'd go up and down but no middle (S1603 AL2S-2M).  I'm pretty sure I found a replacement on Digikey, the exact replacement I mean, where you don't need to order a minimum of 50 of them.  Is this it?  http://www.digikey.com/product-detail/en/ALE1D-2M4-10-Z/563-1201-ND/1792105

Only reason I'm posting is in case other people come across this thread like I did using google looking for the exact same replacement switch.  I hope it helps someone besides me out!

[Spork Schivago]

I also believe this is the replacement plastic cover part for it:  http://www.digikey.com/product-detail/en/140000050624/563-1204-ND/1792108

[rbm]

  I'm pretty sure I found a replacement on Digikey,  ... ALE1D-2M4-10-Z/563-1201-ND/1792105

Unfortunately, the one you've pointed to is a SPDT switch.  It has the proper physical body dimensions however it doesn't replace a DPDT, centre off switch used in the scope.  The part number you supplied decomposes to:
ALE=Lever action
1=1 pole
D=ON-ON
2=PC terminal
M=standard

The NKK switch I spec'ed out in an earlier post is the correct one.  The Copal original is special order only from Digikey.

[Spork Schivago]

  I'm pretty sure I found a replacement on Digikey,  ... ALE1D-2M4-10-Z/563-1201-ND/1792105

Unfortunately, the one you've pointed to is a SPDT switch.  It has the proper physical body dimensions however it doesn't replace a DPDT, centre off switch used in the scope.  The part number you supplied decomposes to:
ALE=Lever action
1=1 pole
D=ON-ON
2=PC terminal
M=standard

The NKK switch I spec'ed out in an earlier post is the correct one.  The Copal original is special order only from Digikey.

Thank you for breaking that down for me!   I really appreciate it!   Man, I really thought that was it.  I tried going to the one you speced out earlier but I couldn't find the part number.  When I clicked the link you had up, it gave me a 404.  I went to their website and clicked on the data sheet, it gave me a 404 too (from Copal's website).

[rbm]

Thank you for breaking that down for me!   I really appreciate it!   Man, I really thought that was it.  I tried going to the one you speced out earlier but I couldn't find the part number.  When I clicked the link you had up, it gave me a 404.  I went to their website and clicked on the data sheet, it gave me a 404 too (from Copal's website).

Try the link again.  I updated it to point to a copy of the file on my GoogleDrive.

[Spork Schivago]

It says I need permission to view.  I requested permission.  You might want to adjust the permissions so everyone can view without having to request permission.   Than again, there might be a reason you have it setup that way.  Thank you though, I think we're getting closer to me seeing the PDF!

[rbm]

Done, made the permission change.

[Spork Schivago]

Thanks!  Also, do you think these are the push button ones on that panel?   I know there's a few different types on that board (three I think).   But this site seems to have a few different types (at least two of the types I would think).

http://www.alps.com/prod/info/E/HTML/Switch/Push/SPPH1/SPPH1_list.html

http://www.alps.com/prod/info/E/HTML/Switch/Push/SPPH2/SPPH2_list.html

What do you think?   Are they the same ones as the ones on that Hitachi panel?

[joneggert]

In case anyone is still looking for a replacement rocker switch for the Fujisoku AL2S, I believe this one will work:
http://www.mouser.com/Search/ProductDetail.aspx?R=A28KB-BHvirtualkey63300000virtualkey633-A28KB-BH

They are in stock and ship same day for under $20.  I'll have mine later this week and I'll post again if it does not work properly.

BTW - Thank you to the OP!  I was about to toss my old scope out, but for $20 and an hour's labor, I think I'll have her working again.

[AF6LJ]

Thanks everyone for sharing this was a great thread.

[rbm]

joneggert, that switch appears as though it will work, electrically and mechanically.  The difference between it and the one I bought is the toggle handle; your switch has a standard metal bat handle.

I checked the same part number on Digikey and it is currently in stock as well.

[pascal_sweden]

Why does the scope have such a long winded grey cable inside?
That winded cable on the right seems miles long

[rbm]

The wound cable is a delay line to give the delay triggering feature of the scope.

[grumpydoc]

The wound cable is a delay line to give the delay triggering feature of the scope.

Not quite, it is a delay line but not to give the delayed trigger.

It is there so that you can see the edge on which the scope triggered for fast signals, most good quality higher bandwidth (certainly anything > 100MHz) analogue 'scopes have them.

[rbm]

Ah, ok.  Thanks for correcting me.

[Robinrayner]

Hi I used to sell these scopes when I worked at stc instrument services sold well against them and I liked them a lot. Back then the trigger lock was a big plus for some users.
I have one now an ex demo unit that saw very little use.
But the uncal knob on the channel a attenuator is broken off. I have removed the board and undone the circlip at the pot end so its an easy task to change it.but making one is a bit of a challenge.just wondered if you might sell me one off your parts scope? I live down in France. By the way I think we used to charge quite a lot extra for the a option. Never new it was that easy to change! Done mine while apart thanks to your info many thanks.

Might even be able to find an old cat here somewhere.

[old gregg]

Hi,

I need to change 3 push/pull pot on my HITACHI VC-6023, instead of creating a new thread I ask here. The reference in the service manual are EVHYK3325B14 which is 10K push pull. Does anyone know the manufacter or a suitable replacement ?

[ulyanoff]

Thank you for your work on Hitachi 1565 - it's great! Tell me in the photo there is a highlight of some buttons of the oscilloscope itself, this is tuning or there is such a modification. Look at the photo. Thank you .

[grumpydoc]

Thank you for your work on Hitachi 1565 - it's great! Tell me in the photo there is a highlight of some buttons of the oscilloscope itself, this is tuning or there is such a modification. Look at the photo. Thank you .

The 'scope didn't have a cover on when I took that photo - it's just light from above shining through the PCB in the 'scope.

[Miti]

About the frequency counter on the Hitachi scopes.
I have a 1585 and I'm frustrated by the frequency counter accuracy too. This model has a PEF-875 board and there's the uC and the frequency counter. I applied 1MHz from a Ublox GPS module and it reads 998.1KHz. If I touch one of the pins of X4101, the blue resonator in the picture, with an oscilloscope probe connected to a reasonably accurate frequency counter, the reading goes up to 999.6KHz and the frequency counter reads 12.006MHz. As you can see in the picture, there's a place for crystal oscillator but they decided to use a ceramic resonator. Really Hitachi? The PEF-875 board seems to have two 32 pins headers soldered to the one beneath so would be pretty hard to remove it and I may damage some pads. Again, really Hitachi?
I, being a bit of a precision nut, intend to desolder the resonator from the top and install a crystal that has much tighter tolerance and stability than a ceramic resonator. By my calculation, the crystal must have a load capacitance of 21.5pF so I don't need to change the two 33pF load capacitors shown in the schematic. A 20pF CL crystal should do it.
I'll let you know how it goes.

[Miti]

The resonator is out, ready to receive the crystal.

[Miti]

All done, the crystal is in and check this out...bang on.
Why did I do it? Do I need this accuracy? Of course not, it is called OCD ... Oscilloscope Compulsive Disorder   

[rbm]

Interesting upgrade.  I have a V-695. I have to see if I can do this modification, or even if it is necessary to do it.  You modified X4101 on the PEF-875 board from a 12MHz resonator to a 12.000 MHz CL crystal if I understood correctly.

I'm not sure of the exact differences in the frequency display hardware between your V-1585 and my V-695.  If my V-695 scope is equipped with a PEF-782 board, would I consider doing this modification to X3101, which is also a 12.000 MHz crystal?

[bitseeker]

Nicely done, Miti. Why did you do it? Because you could. And it looks cool. Sounds good to me.

[Miti]

Interesting upgrade.  I have a V-695. I have to see if I can do this modification, or even if it is necessary to do it.  You modified X4101 on the PEF-875 board from a 12MHz resonator to a 12.000 MHz CL crystal if I understood correctly.

I'm not sure of the exact differences in the frequency display hardware between your V-1585 and my V-695.  If my V-695 scope is equipped with a PEF-782 board, would I consider doing this modification to X3101, which is also a 12.000 MHz crystal?

Most likely that's the ceramic resonators that you need to change. The easy way to validate that, apply known accurate 1MHz and see what the frequency reading you get. If it is bang on, you're good, you don't need to replace anything . Then touch one of the resonator's pin win an oscilloscope probe and observe if the counter reading changes. If it does, that's your culprit.

[rbm]

Cheers!  thanks for the explanation.

[Robinrayner]

Well just brought a vc6025 the digital storage version of the 665 and low and behold the same mode for the frequency counter works perfectly on that.

[ulyanoff]

In search of a good analog oscilloscope I bought Hitachi V-660 on ebay. The device turns on, trigger is work , but the image is distorted. I already study the manual, I ask the advice of experienced specialists - this can be a defect in the CRT tube? . Thank you. Photos from this topic are very similar to my device.
p / s / I think the problem in sweep generator PEF-865.

[rbm]

A first step might be to replace capacitors on the boards.  They might have aged badly.

[grumpydoc]

A first step might be to replace capacitors on the boards.  They might have aged badly.

I'm afraid it looks like physical damage to the CRT

[ulyanoff]

Thank you all. If the CRT tube has physical damage, then I think there is a vacuum loss and no trace is displayed on the screen. All secondary voltages from the power supply unit are checked and correspond to the circuit. After few days I will back with results.

[grumpydoc]

Thank you all. If the CRT tube has physical damage, then I think there is a vacuum loss and no trace is displayed on the screen.

Not always.

The CRT has a number of internal structures made of glass which can be damaged by mechanical shock, as well as the horizontal and vertical deflection plates.

Eg see this thread https://www.eevblog.com/forum/repair/tek-2211-crt-weirdness/ for a 'scope with similar display problems.

[ulyanoff]

A bit sad message, most likely now I'm looking for any version of the CRT Matsushita 150DGB31. How do you think how realistic it is to find? Also additional , maybe someone needs an entire oscilloscope or some parts or block from it. You can consider the option.

[Moonbase]

Seems this thread’ll never die. Ever. :-)

Thanks to all for the teardown, photos and especially the search for S1603!

Unbelieveable how time flies … I’m the proud owner of a VC-1065C for about 30 years now, and guess what: After having neglected my beauty for about 10 years now, I took it into service again and promptly S1603 (the selector switch) stuck—in SINGLE mode! Aargh!

I’m a sentimental guy. Guess I want to spend a few more years with this beaut old lady … So, please, anyone got a spare with the original paddle? Or do I have to try DigiKey’s 360-3390-ND (A28KB-BH)?

It wasn’t clear from the above if the poster had luck with this part. Would it be a functioning replacement for the original? Or did anyone find a switch where I could reuse the old original olive-coloured paddle with?

Thanks!

[SilverSolder]

LOL, all the old Hitachi scopes are coming out to play.

I have a V-660 that still comes in handy as an extra couple of channels in some situations.  It was an eBay find about 15 years ago... 

It has always had a "weak" selector switch - not bad enough to outright require repairing, but mildly irritating nevertheless (on an otherwise excellent scope).

Good to see it can be fixed,  this thread has inspired me to take a look!

[rbm]

Or do I have to try DigiKey’s 360-3390-ND (A28KB-BH)?  ... Would it be a functioning replacement for the original?

Hi,  This NKK A28KB-BH switch from Digikey should be a drop-in replacement for the OEM Fujisoku ALE2S-2M4-10-Z paddle switch. It was for me (see Posting #32).  The switching  configuration (DPDT-Centre off) and mechanical properties (2.54mm contact spacing and 5.08mm row spacing, switch body height and paddle size) are all equivalent.  You can purchase with confidence.

[Moonbase]

Thanks a bundle, Robert! Your confirmation is much appreciated.

I wonder if I should order two of those, to find out if it was possible to somehow adapt the original paddle to it … :-) I just like it when things look original again, I guess.

In general, I’m really impressed with the quality of the V-1065C. Bought new about 30 years ago (unbelievably expensive then), 20 years of service, survived about 5 times moving house and 10 years of hibernation in the cellar and still as good as ever (well, except the switch which stuck a few days ago). All caps still fine, inside looks beautiful, all switches (except S1603) good, BNCs shiny, intensity good, and focuses as sharp as a needle still. Wow.

[arw]

I also did the same freq counter hack on a VC6025 and it worked.
Was a pig to get to the links as they are under an add on board.
This daughter board has four standoff wires to secure it to the motherboard, cutting two of these enabled the daughter board to be lifted enough to get to the links. However putting it all back and resoldering the cut standoff wires,  I am fairly sure the trace is now not as pin sharp as it was before.
No amount of focus, intensity or astigmatism ajustment would bring it sharper.
A lot of cables had to be moved to get the board out enough to do the mod, so possibly the cable routing is quite critical in some area.
Will have to spend some time to debug this. A case of if it ain't broke don't fix it!

[ulyanoff]

Hello guys! Maybe the author will tell you how to remove the handle v / div? Just vertically pull fails. Hitachi V-6025(Grundig SO50) Thanks !

[ulyanoff]

Hello guys, does anyone have a broken oscilloscope from the V660, V665, V695, V1065 series, or maybe you know where you can buy the front frame and filter of the oscilloscope? Thanks

[wn1fju]

Old post, but I just recently came across it.  I can confirm that the hack mentioned earlier to enable the frequency counter also works on the 60 MHz Hitachi V-665 oscilloscope. 

It was fairly easy to do without first swinging the power supply out of the way.  I merely reached in there on an angle, cracked off the existing zero ohm resistor and soldered a jumper wire across the adjacent pair of pads.

As also mentioned before, there is an inaccuracy with this enabled option.  Mine reads consistently 0.55% low.  That is, a 1000 Hz waveform reads 994.5 Hz, a 10 kHz waveform reads 9.945 kHz, ...., a 10 MHz waveform reads 9.945 MHz.  When making measurements using the cursors (1/T), I do get the correct numbers, however.  The frequency measurement option appears only to go down to a lower limit of 50 Hz.

[pbs74]

Since this thread got resurrected anyway, it seems to be the only one for this model on this great forum, and I happen to own the basically similar v1565 model that is shown in this new video that forum user oz2cpu added to his YouTube channel today, I am going to add a link to it here as reference for any future readers. The video covers most of the functionality, along with high level tear down:
 

[wn1fju]

pbs74:  Very nice video, thanks.

Yes, I did have to consult the manual on the somewhat puzzling way of using the toggle switch and the adjacent knob.

I have resurrected a few Asian-produced analog scopes (BK Precision, EZ, Iwatsu, Leader, Phillips, Tenma), as well as the usual USA Tektronix and HP units.  I find the HItachi scope among the best.  Fortunately, my V-665 mostly worked when I got it (needed some cleaner sprayed in the pots/switches).  It looks a little challenging to rip it all apart for servicing.