HP8563E repair

[charlyd]

hi i got an hp8563E with some errors. lets number them 355,317,319,356,351,335.
i also saw my picture is fading away after some time
althought at the start of power on it is not that good i think.

i did the tube checks with the press module press softkey #x
and adjust a pot on A17. this all was ok. what more checks can i do to be sure my picture is like...
the pictures look very ok but are NOT... they are very dimm.

when i power on it is fading away after some 10 minutes, i only see the square line the textboxes are not visible anymore.
is this a tube fail effect  or do i need to check so components (=read testpoint) on the A2 or A17 board

any tips because from what i saw this is happening often...

[charlyd]

i have no output at all visible on the screen.also no cal si gvnal..what steps can i do to find the signal.. and make my problem small.
i checked the output from my yig oscilator to a counter
it gave me an frequenty of arround  5.780Ghz by +10dbm.

what can i test more...

[james_s]

It's possible to develop a tube fault that causes the picture to fade out after a time, intermittent connection to the screen grid (G2) can do that. It's rare though, normally a worn out tube is dim when you first turn it on and takes longer than usual to warm up. Another telltale symptom is that the focus will go soft when you turn the brightness up.

[charlyd]

what happens is... i checked the basic steps written in the manual.  with the soft keys and so.. and adjustments on the pots of the A17 driver board. all seems good to me.

but from the start when powered-on the higlighted line in het bottom is ok. the rest is blurry and fading by the minute...after some 15 minutes it is getting darker and darker….especially the grid…..when i power off. and after 15 minute power on it is better for short while but then dies again.. by the minute

any tips?  or do i need to order a tube?

[charlyd]

apart from my tube problem…..there is a post i found (see below)   

i have the same series errors like 355, 351, 353, 319, 317, 356, 335 and the same sympthons....

because i see not input on the screen i did a quick check on the direct output of the YIG oscilator it give me arround 5.780Ghz at about +10db.

this post is about a 8560E, but many boards are the same
The fault is the analyzer will not display any input signal including the calibration input signal. You will also have numerous errors like 355, 351, 353, 319, 317, 356 and 335. Your mileage will vary. Might have less or more errors.

In 8 months, I bought two different 8560E analyzers off of ebay from different sellers. Once I received them and checked them out, both had the symptom listed above. I bought the second one because the display was still nice and bright compared to the first one I purchased and it was cheap. These analyzer are known for having dim displays. Anyway, both units had the same symptom of no input signal showing on the screen and it turned out that both had the same faulty part.

Bottom Line: Go to the A15 board and look at the J701 output. Should be 600Mhz AND around -3dbm to +5dbm. Both of my units were spot on 600Mhz BUT the levels were around -20/-25 dbm. After some troubleshooting, the problem was U700.

After replacing U700 on both units, the errors went away and the analyzer worked as it should. U700 is just a RF amp on the A15 board. It's under one of the metal shields/heatsinks in the 100Mhz distribution section. The 100Mhz gets doubled, then tripled to 600Mhz.

U700 is a MSA-0505. I purchased genuine HP parts from a seller on ebay from Israel. There are others from China but who knows if they are genuine.



Is this fix also related to the 8563E, to call it by its name: did someone ever use this fix in a 8563E?

all tips to check and isolate my problem are welcome.. 

help on how to easy check my
- 1st mixer (5087-7032)
- low dis. ampl. (5086-7885)
- 2e conv (5086-7957)

[james_s]

That doesn't sound like a problem with the tube itself to me. I am not familiar with those specific instruments, just general CRT technology.

[4thDoctorWhoFan]

apart from my tube problem…..there is a post i found (see below)   

i have the same series errors like 355, 351, 353, 319, 317, 356, 335 and the same sympthons....

because i see not input on the screen i did a quick check on the direct output of the YIG oscilator it give me arround 5.780Ghz at about +10db.

this post is about a 8560E, but many boards are the same
The fault is the analyzer will not display any input signal including the calibration input signal. You will also have numerous errors like 355, 351, 353, 319, 317, 356 and 335. Your mileage will vary. Might have less or more errors.

In 8 months, I bought two different 8560E analyzers off of ebay from different sellers. Once I received them and checked them out, both had the symptom listed above. I bought the second one because the display was still nice and bright compared to the first one I purchased and it was cheap. These analyzer are known for having dim displays. Anyway, both units had the same symptom of no input signal showing on the screen and it turned out that both had the same faulty part.

Bottom Line: Go to the A15 board and look at the J701 output. Should be 600Mhz AND around -3dbm to +5dbm. Both of my units were spot on 600Mhz BUT the levels were around -20/-25 dbm. After some troubleshooting, the problem was U700.

After replacing U700 on both units, the errors went away and the analyzer worked as it should. U700 is just a RF amp on the A15 board. It's under one of the metal shields/heatsinks in the 100Mhz distribution section. The 100Mhz gets doubled, then tripled to 600Mhz.

U700 is a MSA-0505. I purchased genuine HP parts from a seller on ebay from Israel. There are others from China but who knows if they are genuine.



Is this fix also related to the 8563E, to call it by its name: did someone ever use this fix in a 8563E?

all tips to check and isolate my problem are welcome.. 

That was from my post regarding the 8560E.  I have no idea how it would relate to the 8563E.

As I stated, I had the same fault on the A15 board on both analyzers.  If your A15 board is the same, check the output from J701.

[charlyd]

Hi i checked out J701 and guess what i see a 600Mhz very low in ampl. something like -60 or so..
can somebody help me with the CLIP 08563-60132 (the artek manuals version the 8560E clip version doesn t have outlines )

[4thDoctorWhoFan]

Hi i checked out J701 and guess what i see a 600Mhz very low in ampl. something like -60 or so..
can somebody help me with the CLIP 08563-60132 (the artek manuals version the 8560E clip version doesn t have outlines )

Not sure what you mean by "outlines" but the artek clip version I have for the 8560E has both the layout and schematics for that board.  So, I'm a little confused by your terminology of outlines.

Actually, at -60dbm I am surprised you were able to see the 600Mhz signal.  Use the service manual and go back further down the line.  In order to get a proper 600Mhz signal at the correct amplitude, the 10Mhz reference must be correct, the 50Mhz signal and the 300Mhz signal.  The 600Mhz at J701 is derived from the 300Mhz signal and it all starts with the 10Mhz.

You might have a different problem since my two units, I was getting about a -20/-25 dbm signal from J701.  Your measurement of -60dbm is really low.  Practically non existent.

[charlyd]

Hi thanks for your reply i will have a look again later if the -60 was really -60 or a bit less i wrote it down when i was not on the bench anymore…

but this is what i mean with no outlines.. i took a picture where it is very bad but het hole manual has it..  missing component outlines
left is a screenshot from the web which is ok. right the manual..(same picture..)

[4thDoctorWhoFan]

I see, the component outlines on the schematic are missing.  That is odd.

Couple of quick questions:

1)  How and what did you use to measure the 600Mhz signal out of J701.
2)  When you measured the signal out of J701 were all the big RF shields/heatsinks still attached to the A15 board?  The signal out of J701 will be way off if you measured it when the shields were removed.

[charlyd]

before i forget...powered on hours over 60000 hours.
so i can imagine that my tube is gone. A good one is on its way.
i measured J701 with all rf shields closed and the real cal output is -28db it should be -10db.

a question to 4thdocterwhofan. what can i measure with rf shield of?  what are the values on u701 u702 u501 ..


btw you say heatsinks and yes it was getting warm. am i allowed to power on for longer time or is it ok because the shield is just getting warm because warm air was closed in the shield and just warming up.

[4thDoctorWhoFan]

before i forget...powered on hours over 60000 hours.
so i can imagine that my tube is gone. A good one is on its way.
i measured J701 with all rf shields closed and the real cal output is -28db it should be -10db.

a question to 4thdocterwhofan. what can i measure with rf shield of?  what are the values on u701 u702 u501 ..


btw you say heatsinks and yes it was getting warm. am i allowed to power on for longer time or is it ok because the shield is just getting warm because warm air was closed in the shield and just warming up.

-28dbm is more reasonable.  It's still wrong and low but much better than -60dbm.  The -28dbm is in line with the  two faulty units I had.  My two faulty units were reading around -20/-25 dbm.  Normally, this should be closer to 0dbm give or take 6dbm.

It's looking like your unit might have the same faulty part as my two units.  Very interesting. 
Since your fault is looking just like mine, I would measure the signal at U700 which was the bad part on my two units.  Take off the RF shield and using the schematic you will be able to find the input and output of this part.  If the measured output is equal or lower than the input, it's bad.  You should see a lot of gain out of this RF amp.  No need for precision here.  Just a relative large gain on the output compared to the input.

If I remember correctly, the part has an 05 stamped on the top if it.  The part number is MSA-0505.  I think the only place I was able to find original HP parts was from a seller on ebay from Isreal.  The prices were cheap and parts were excellent and new.

Those RF shields do get very warm to hot.  It's normal.

[charlyd]

thanks for you reply.. i will add the pictures for other members. to give it a view ;-)

and yes you are right the "5" stamped on it ;-)  i made myself a sort of probe for my 8595E to drill down the trace..because i don t have a active probe or other better choice.  were all voltages ok on your both units?  btw i found all the MSA models used..

i have still problems todo a measurement of ampl. in the dBm in the circuit. any tips  with passive probe signal gets all over the place. with selfmade probe i also really can t see the difference in input and output.

[4thDoctorWhoFan]

thanks for you reply.. i will add the pictures for other members. to give it a view ;-)

and yes you are right the "5" stamped on it ;-)  i made myself a sort of probe for my 8595E to drill down the trace..because i don t have a active probe or other better choice.  were all voltages ok on your both units?  btw i found all the MSA models used..

i have still problems todo a measurement of ampl. in the dBm in the circuit. any tips  with passive probe signal gets all over the place. with selfmade probe i also really can t see the difference in input and output.

I just cannot remember how I measured the amplitude on U700.  I didn't have another spectrum analyzer so I probably used my power meter with a make shift probe attached to the power head.  It was probably just a piece of coax. 

Anyway, if you are not seeing a significant difference in amplitude between the input and output of U700, then I would say it's bad.  It's a very high gain RF amp.  In fact, it has 18dbm of amplification.

This should be noticeable even with home made probes.

[charlyd]

@4thDoctorWhoFan  Just a question, do you maybe have written down some measurments from that area when you did the project..
so i can compare a bit  ( having not really a good probe.) i saw the input was arround -1 dBm  output 0dBm...but ??  when i look at the others in the chain like U501. i see the same behaviour.
my -VREG is = -13v, my tuning voltage is 13v. onces repaired i wil for sure make some notes for future repaires and post then here.

[4thDoctorWhoFan]

@4thDoctorWhoFan  Just a question do you have some  writtn down measurments from that area when you did the project..
so i can compare a bit  ( having not really a good probe.)

No, unfortunately I did not take any notes.

If I remember correctly, the schematic lists some dbm levels & voltages and I think they were all in the ballpark.
I did not have any special equipment either.  Just a home made "probe".  I remember the output of the RF amp U700 being either the same or lower than the input.  The input was in the ballpark of what is listed on the schematic.  You should see a BIG difference between the input and output as U700 has 18dbm of gain.

If the input of U700 looks approximately normal as far as amplitude, I would just replace it.  The part is cheap and only takes minutes to change.

[4thDoctorWhoFan]

@4thDoctorWhoFan  Just a question, do you maybe have written down some measurments from that area when you did the project..
so i can compare a bit  ( having not really a good probe.) i saw the input was arround -1 dBm  output 0dBm...but ??  when i look at the others in the chain like U501. i see the same behaviour.
my -VREG is = -13v, my tuning voltage is 13v. onces repaired i wil for sure make some notes for future repaires and post then here.

Your input of -1 dbm is probably ok.  With the RF shield off, there will be lots of loss.
The U700 is in the 100Mhz section, so perhaps using an O-scope will work better for you.  This might be what I used but I don't remember.  With the scope, you should be able to get a decent frequency & amplitude measurement.

As far as voltages go, I would just make the 15V rails are working.

[charlyd]

hi i think it is time to order the msa-0505.
but what is an O-scope.  btw i order a 1152A active probe, for future cases like this.

[4thDoctorWhoFan]

hi i think it is time to order the msa-0505.
but what is an O-scope.  btw i order a 1152A active probe, for future cases like this.

O-scope = Oscilloscope
U700 is only in the 100Mhz section.

[charlyd]

ah yeah lol of course.  U700 is in the 100mhz circuit but in the tripler or doubler circuit i don t see much difference in gain betweens inputs and outputs ...like for example U501

[4thDoctorWhoFan]

ah yeah lol of course.  U700 is in the 100mhz circuit but in the tripler or doubler circuit i don t see much difference in gain betweens inputs and outputs ...like for example U501

U700 is the main RF power Amp.  The others like U501 don't have nearly the same gain.  Also, if U700 is not working, you are going to have much smaller signals for the amps down stream like U501.  Plus, the RF shield is off, so even lower levels.

Just my thoughts.  Take it with a grain of salt. Good luck.

[charlyd]

thanks 4thDoctorWhoFan, i will go for the U700 ( ordered it already and have to wait a while i assume) i was just wandering if i can do some checks on the circuitry  left of the U700.   added a part schematic from what i see now..  will add one after replacing U700.
btw found a good schematic on keysight. (08563E-60091) My board is the (08563E-60132).

...will come back on this one after parts has arrived…...

[charlyd]

Hi ok with all errors gone, i am back at the last part.  "the Display Brightness"

i have read in other topics things about U207 and U210. but after a swap that didn t work out for me. i discovered that when i lift out U207 pin 1 (brightness) switch line or even better U207 pin 8 also a switch line my picture looks very good. the DEF1 signal line is TTL high where the low is needed to get a good picture. really strange. this line apears to come from the 74HCT377 chip.

any suggestions?

better go on with this threat and close it here
https://www.eevblog.com/forum/repair/hp-8563a-spectrum-analyser-display-itensity-problems/msg3305780/#msg3305780

[charlyd]

Ok it is a while ago but in the meanwhile i swapped out the video ram chips. This because i was told that my error could lay there....

but pitty no it is not my video ram.

so any more suggestions?