Electronics > Repair
Fluke 343A repair
<< < (4/12) > >>
Rax:
This unit needed its HV rails electrolytic capacitors replaced. With those replaced, the unit works without a hitch.

Interestingly, in circuit all those caps seemed to measure correctly. I guess the lesson to be learned here is to take those in circuit measurements with a grain of salt. And the SM fault finding procedures as well. But it is important to observe that the common from your meter needs to go to + SENSE, which internally is ground for this instrument.

Before I got those HV caps delivered, I've also replaced all electrolytic capacitors everywhere else. This unit is now ready for very long trouble-free service.
Rax:
Well, that success was short lived. I had it running for quite a while with no issues, so stable that I started considering adjustments, and just now I turned it on and it seems to output 150V-200V regardless of the "voltage out" setting. Right when this issue started occurring, it's switch to the LIMIT ON mode, now it's not, but the unruly output is still there.

Back to the drawing board.
bastl_r:
Hi
Did you changed al of the HV-caps?
In my 341, the 450V electrolytic capacitors were all almost at the end and when the 250V electrolytic capacitor C3 died, the calibrator failed.

bastl_r
daisizhou:
You need to take some pictures and videos to let everyone know about this 343A so that everyone can help you
Rax:

--- Quote from: bastl_r on June 13, 2024, 06:18:53 am ---Hi
Did you changed al of the HV-caps?
In my 341, the 450V electrolytic capacitors were all almost at the end and when the 250V electrolytic capacitor C3 died, the calibrator failed.

bastl_r

--- End quote ---

I actually replaced all of the electrolytics. The job is relatively easy and having the unit open, I thought why not give it many years of future service.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod