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8560E A14 Trouble

Question asked by 4thDoctorWhoFan on Mar 6, 2016
Latest reply on Mar 8, 2016 by PA0ALV

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I believe I have an issue with my A14 board.
Can anyone provide the schematic & layout? The A14 board is 08560-63069.
The serial number for the analyzer is 3611A02098.

I purchased the latest CLIP thinking all the revisions would be listed but no, that is not the case. How disappointing that my board was not listed.

Before I describe my problem, one quick question before I forget. Is any cal data lost if the battery failed while the unit was off?

Initially, the display was dead. I repaired the A6 power supply as there was a bad Q310 MOSFET for the +15V line.
The problem now is that there is no signal being displayed when I provide an input. Also, after the unit boots up, there are six errors: 356, 334, 319, 317, 353 & 351.

I have done some troubleshooting and I do have the 10Mhz into the A14 board. I also have the 300Mhz & 600Mhz signals. The cal output is also functioning. I have no way to test the YIG as I don't have the capability to test signals above 3Ghz.

I noticed that I am not getting a low sense voltage reading on the LODA. The bias voltage is there but zero voltage on the low sense line on the LODA. Does this voltage come from the A14 board or is it a sign of a bad LODA?

Any help would be appreciated as I have never had to troubleshoot such a complicated piece of test gear before.
Thanks,
Tony

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4thDoctorWhoFan Mar 6, 2016 11:12 AM

I have been doing some troubleshooting by following the troubleshooting procedures in the service manual and here is what I found so far.
The procedure is the A7 LODA on page 589 of chapter 11. This is the procedure where you remove the cable (W12) from the A14 board connector (J10) and hook up some jumpers and measure some voltages.

Everything was as it should until step 6 where the voltage measured should be more positive than +12.3 volts. I am only measuring +4 volts. The previous step 5 was okay where the measured voltage should be more negative than -9.4 volts. I measured -13 volts.

I don't know exactly what this means but any input would be appreciated.

Thanks,
Tony

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PA0ALV Mar 7, 2016 12:07 PM

Hi Tony,

Read your problem. I had nearly the same with a 8563E probebly the same A14.
I have a reply on the thread 8563E with .jpg's of de particular defect parts. two diodes.
After repairing the YTO. Band tuning of the YTO did not work.
I had no schematic diagram of the A14 so it was a lucky shot to see the brown colored items.
Replace those analyser fb.
So please look at the thread 8563e reply by pa0alv

succes
Ary

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4thDoctorWhoFan @ PA0ALV on Mar 7, 2016 3:36 PM

Thanks for your reply.
The two diodes you mentioned look fine & test okay on my A14 board.

What did you mean by "replace those analyzer fb". What is fb?

Thanks,
Tony

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PA0ALV @ 4thDoctorWhoFan on Mar 8, 2016 1:22 AM

Hi Tony

It had to be:

"replace those, analyser fine business"
So after replace the diodes the analyser works fine.

Hereby earlier conversation about 8563:

It took some time to calibrate the YIG's frequencies followed procedure per manual.
But, I could not adjust the high frequency. 5,8775 GHz instead of 6.01 GHz.
So reading and thinking and measuring different voltages. But all ok. By examination of the A14 board I noticed two Q301/Q302
Followed the tracks as good as possible around the variable resistors and I presumed, one for each, FM and Main coil, measured the surrounded components. Nothing seems wrong.
At last I removed two diodes, the 20 V zenervoltage was within limits and appr. 200 Ohm's in forward direction but in reversed direction app. 5K . !
So replaced and all works well.

success

Ary

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4 Replies

4thDoctorWhoFan Mar 6, 2016 11:12 AM
Mark Correct
Correct Answer
I have been doing some troubleshooting by following the troubleshooting procedures in the service manual and here is what I found so far.
The procedure is the A7 LODA on page 589 of chapter 11. This is the procedure where you remove the cable (W12) from the A14 board connector (J10) and hook up some jumpers and measure some voltages.

Everything was as it should until step 6 where the voltage measured should be more positive than +12.3 volts. I am only measuring +4 volts. The previous step 5 was okay where the measured voltage should be more negative than -9.4 volts. I measured -13 volts.

I don't know exactly what this means but any input would be appreciated.

Thanks,
Tony
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PA0ALV Mar 7, 2016 12:07 PM
Mark Correct
Correct Answer
Hi Tony,

Read your problem. I had nearly the same with a 8563E probebly the same A14.
I have a reply on the thread 8563E with .jpg's of de particular defect parts. two diodes.
After repairing the YTO. Band tuning of the YTO did not work.
I had no schematic diagram of the A14 so it was a lucky shot to see the brown colored items.
Replace those analyser fb.
So please look at the thread 8563e reply by pa0alv

succes
Ary
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- 4thDoctorWhoFan @ PA0ALV on Mar 7, 2016 3:36 PM
  Mark Correct
  Correct Answer
  Thanks for your reply.
  The two diodes you mentioned look fine & test okay on my A14 board.
  
  What did you mean by "replace those analyzer fb". What is fb?
  
  Thanks,
  Tony
  Like • Show 0 Likes0
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  - PA0ALV @ 4thDoctorWhoFan on Mar 8, 2016 1:22 AM
    Mark Correct
    Correct Answer
    Hi Tony
    
    It had to be:
    
    "replace those, analyser fine business"
    So after replace the diodes the analyser works fine.
    
    Hereby earlier conversation about 8563:
    
    It took some time to calibrate the YIG's frequencies followed procedure per manual.
    But, I could not adjust the high frequency. 5,8775 GHz instead of 6.01 GHz.
    So reading and thinking and measuring different voltages. But all ok. By examination of the A14 board I noticed two Q301/Q302
    Followed the tracks as good as possible around the variable resistors and I presumed, one for each, FM and Main coil, measured the surrounded components. Nothing seems wrong.
    At last I removed two diodes, the 20 V zenervoltage was within limits and appr. 200 Ohm's in forward direction but in reversed direction app. 5K . !
    So replaced and all works well.
    
    success
    
    Ary
    Like • Show 0 Likes0
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8560E A14 Trouble

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