Ono Sokki CF350 FFT : repaired

[psykok]

Hi,


I just scored a nice faulty FFT analyzer from Ono Sokki.
Currently the device is still under way but I hope I will get it next week.









I don't now what is exactly broken.
I just now that the analyzer is not switching on any more and was working before the failure ... maybe the psu is broken.

I was just wondering if someone has some document for this unit?


Regards,

Alex

[EEVblog]

I used to have one of these and the full service manual, but sold it, sorry 

[psykok]

 

I used to have one of these and the full service manual, but sold it, sorry 

 

[psykok]

Hi,


I received the FFT analyzer yesterday morning.
It's a pretty heavy beast, build like a tank 

Following the description of the vendor I first checked if the instrument is powering up and ... no.

I open it and checked the psu and nothing at the output ... definitively dead.
Some pics of the broken psu:



To make other tests I only need 5 voltages rails : +5v, +15v, -15v and +12v
So I used my lab psu to check if the instrument is booting.
And no, I get a bip from the buzzer located on the cpu board and after that nothing, the screen and the front panel remain black.

If I turn the CRT button to the max I got something on the screen :


I will make some HD pics of all board next WE.

What can be the next debug step ?



Alex

[poorchava]

Perhaps the PSU has some sort of 'power good' output, which you would also have to emulate in order for the instrument to boot up?

[psykok]

Hi,

I don't see any special cable for a  'power good' ouput.

I have only two connector on the psu:
J2: -15v, gnd, gnd, +15v
J3: 5v, 5v, 5v, gnd, gnd, gnd, 12v


Alex

[vk6zgo]

Hi,


I received the FFT analyzer yesterday morning.
It's a pretty heavy beast, build like a tank 

Following the description of the vendor I first checked if the instrument is powering up and ... no.

I open it and checked the psu and nothing at the output ... definitively dead.
Some pics of the broken psu:



To make other tests I only need 5 voltages rails : +5v, +15v, -15v and +12v
So I used my lab psu to check if the instrument is booting.
And no, I get a bip from the buzzer located on the cpu board and after that nothing, the screen and the front panel remain black.

If I turn the CRT button to the max I got something on the screen :


I will make some HD pics of all board next WE.

What can be the next debug step ?



Alex

You have a CRT type display by the look of it------the good news is your display seems to work.
It is just free running,without any Horizontal or vertical sync,plus it is being blanked off.

If the pix of the display is using the internal PSU,you at least know that "sort of" works!

[psykok]

Yes the CRT is using at least the 12v.
I used a separate psu only for the 12v rail and only with this source connected the CRT is giving the same output.


If I understood the screen is running without input ... for me it means that the mainboard is not up ... the boot possess is hanging.

[psykok]

Hi,

I have made some better pics yesterday

[psykok]

Hi,


After a long time I worked again on the SA this weekend.
I started again to check all caps on the PSU and surprise I found the faulty caps ... the first time I forgot to check two little b....d hided behind a large component.
At this point the instrument was starting again but the screen was displaying same strange pics and jumping like a jack in the box. The screen psu was also producing some high freq sound, like a SMPS with bad caps  (it's always a cap story)


I checked also all caps on the screen psu and found two bad one.
After having replaced these two caps I started quickly the SA to check if the screen was also back ... and yes everything was god.


After mounting again all parts back in the case and made some adjustments on the screen, I can say that the SA is now working again.
Now I have t understand how it really works.


Alex

[vk6zgo]

Great job,Alex!

[Vgkid]

Great job, impressive unit.

[psykok]

Great job, impressive unit.

Hi,

yes it's a really big beast, around 20kg 
My tek 2245 scope look like a toy next to the SA.


Alex

[drtube]

Hello,

Do you have the manual for this fft analyzer? I got the same unit from an auction few days ago but they didn't have the manual..

Thanks

[psykok]

Hi,


No I never manage to get the manual for this unit.


Alex

Sent from my Nexus 6P using Tapatalk

[drtube]

Hello psykok, I sent you a PM just minutes ago, please read it. Thanks

[balu]

Hello,
Since last week I got a new test gear - Ono Sokki CF-350 with some problems. The gear will not power up and had a lot of housing damages.  Yes, this unit came with no manuals or other information.

I’m looking for a manual or service documentation and can’t find anything at the internet.

Any tips were to find some documentation for the CF-350? 

[balu]

Hello,

I have some pictures of optional addons for the CF-350.

The first addon is a memory module with 4x8 32 kByte SRAM (1 MByte total). The other addon is an external disk interface.

[balu]

And one more option for the CF-350.

[slbender]

Did anyone ever come up with some docs ( OP /  SM ) for using or repairing the CF-350???

I just got myself one of these CF-350 sets for my birthday coming up soon ;-).

I suspect Step #1 - take off the cover and clean it inside and out, also the rear fan filter.

Step #2 - may need a new 3.0 v Lithium battery, this set is now around 25 to 30 years old and those Batts were supposed to last 5 -10 years!

Step #3 - check for bulging caps, even if it comes to life.

Step #4 - get out the Sencore PR-570.

Anyone have a suggestion for Step #5 before I apply power?

The Ono Sokki set has not arrived yet, but was reportedly working before it was shipped out.

Does anyone know if it formats a 3.5 inch disk, (single sided or double sided?) or just writes to an MS-DOS disk?

I hope the disk is to save screens; and not to load the software to make the set "go" like some other types of test equipment sets?

Fingers crossed!!!


Steven

[psykok]

Hi,

I tried to replace my faulty floppy drive on my unit with different PC one but without any luck. It's still not able to write one floppy.
I kind of give up with that because I will not really use it.


I have some documentation but I'm not sure if it's complete.
Unfortunately I don't own the service manual and I'm not sure if it has been available in the past

 Anyhow you will see this instrument is great and even without manual you are more or less able to find your way in the menus.
I like it maybe more than may HP which is so complicated to operate, the only bad think is the bandwidth limitation which is sometime a little bit painful.


Alex

[slbender]

Well surprise, surprise, my Ono Sokki CF-350 FFT Analyzer came a couple of days early.  Nice and clean inside. The Lithium battery has a February, 1990 date code, and it's not a 350z, like the set Alex repaired, so it's an earlier set.  That 3 Volt Lithium battery on I believe board #3... currently measures 0.228 Volts ( Quite Dead, Dead, Dead ).

I ordered a cheaper 3 volt battery, the larger Lithium button cell CR2450, it's rated at about 550 - 600 mA versus 1500 mA for the original CR12600, but I just didn't feel like spending $11.00 - $15.00 on a battery.  I am hoping that the CR2450 will last 5 to 8 years, instead of 10 - 12 years, at 1/3rd the price and a few minutes work attaching wires to the button cell socket and encasing the battery and socket in shrink wrap.  My 350 unit seems to be able to be hooked up to 12 - 30 Volts DC. via a military looking socket on the rear, and separate 15A input fuse.  It will apparently connect to an external monitor via a BNC., and what looks like a SCSI 50 pin connector to an external drive (Floppy or Hard Drive?)...  I also ordered an 80 mm fan filter, as the old one was turning to dust when I touched it.  I still have not applied power, I'm in no rush.

Steven

[psykok]

Hi,

I scanned the user guide for the CF-350 :
https://drive.google.com/drive/folders/1wVK5fENgZajeUe-ZxhEMYJaDA4AUBVeT?usp=sharing

[slbender]

Hi Alex -

Thanks for all of those great pictures of the CF-350 internals.  My unit appears to be working.  I made up a battery from a 2450 button cell and soldered it in place of the dead battery.  My set may have one of the available options inside, I think it does show a 3d "Waterfall" sort of display, and has terminals to maybe bypass the internal switching supply, or perhaps it is an auxiliary input to power that supply from a low voltage car battery, or other external battery source, not sure how long such a battery would last, likely 12 volts at 10 amps (120 Watts) would last about half an hour, to one hour.

Since I only had it on once so far, I was pushing buttons at random, and I didn't get very far.  Also, the manual may be of some help in understanding the unit. I have to say, it is incomplete, as you only scanned every "odd" page, omitting the "even" pages.  So half the information is missing, like pages: 1-2, 1-4, 1-6, etc.  I wonder if you would be willing to do the "even" pages (if you have them) so I could print them all via double sided???  Still half a manual is way better than none ;-.

Thanks,

Steven

[psykok]

Hi,


Sorry I have not noticed that I had only half the manual:(

Sure I will do it again.


Alex