Electronics > Repair

HP8563E spectrum analyser-Repair log.

(1/4) > >>

Here I will document my efforts to repair the HP8563E spectrum analyser that I recently purchased.
In progress so far:
1/ Power supply board removed and capacitors ordered from Farnell (UK) and Digikey. I have tried to obtain capacitors rated at 10K hours when possible. I will post an annotated picture of the power supply board later that clearly shows the original values of the capacitors and another photo of the board when it has been recapped.
2/ Removed A17 CRT driver board and cleaned/inspected it for any signs of damage. No damage detectable.

Up next.
1/ Recap the A6 power supply board (I'm waiting for the parts to arrive  on Thurs/Friday). Test removed capacitors for capacitance and ESR. No sign of leakage or bulging.
2/ Remove/clean/replace all board to board connections one at a time. I'm using WD40 Specialist contact cleaner and then applying Servisol Super 10 switch lube. I'm hoping this does some good.
3/ Replace the power supply PCB in the chassis and power the unit up.
4/ If the CRT still does not work, carry out a series of checks documented in the service manual.
More later.

Good luck!

I have two broken HP 8594E which I was unsuccessful in repairing them. Luckily I bought three and the third one is indeed working, so I keep the other two for spares or for the day I manage to repair them...


So, I've recapped the power supply (well the Aluminium electrolytics anyway-left the tantalum and others to case by case if needed). Just testing the power supply now by using a custom-made dummy load PCB that I've made (details available if needed).
Spent a couple of days trying to trace a problem on the -12.6v line. Turned out that the TP305 test point is mislabelled on the PCB(the label is at the cathode of diode CR314 (which connects to the ground pin on the 7912 regulator) which measure -0.6v (correct). However, the TP305 test point (which is CORRECT on the schematic) is meant to indicate the -12.6v line voltage. This -12.6v can be found at the cathode of diode CR308 (which is also the output of the 7912 regulator) and this does indeed measure -12.9v (unregulated with no substantial load on the power supply). The input to the 7912 regulator (which sources current) measures -18.2v (nominal -17v from the rectifier).
So, the lesson is to double-check what the manual and schematics say and cross-reference it to the ACTUAL pcb.
Next is to apply loads to the various voltage rails using my dummy load pcb and my GPP-4323 power supply. And also I will be checking various waveforms just for curiosity and to rule out/confirm the supply as the source of the no display fault.

Martin Miranda:
subscribing.  :popcorn:

Will be good to see dummy load details...  8560E PS s/b similar...


[0] Message Index

[#] Next page

There was an error while thanking
Go to full version