First suspect is always the small electrolytics on A10, followed by the large one on A10, and large one on A3, but those last 2 are large/high qual and seem to last much better.
All 6 of my 3456As had or developed issues with one or more of the small caps. All 6 have been re-capped with <part id> <original P/N and spec> <replacement P/N> A10C7 0180-3009 47uf ±20 50vdc Al Nichicon UPM1J680MPD6 A10C8 0180-2803 100uf +50/-10 50vdc Al Nichicon UPM1J331MHD6 A10C13/A10C15 0180-2635 1000uf +50/-10 35vdc Al Nichicon UPM1V152MHD6 A10C16 0180-3014 330uf ±20 50vdc Al Nichicon UPM1J391MHD6 A10C19 0180-3008 470uf +50/-10 35vdc Al Nichicon UPM1V681MHD6 These are all direct match for lead spacing/etc except C8, where the replacement is wider leads _but_ has a thick slotted base so you can dog-leg the leads to match the original spacing. All are long-life ± 20% parts, all are larger but fall within the original range spec except C8, where going from 150uf (originally selected part) to 330uf reduced p-p ripple from .45v to < .2v DO check voltage and ripple, but if it comes down to it, the re-cap takes about 20 minutes, including removing A10, pre and post recap cleaning and re-install. On 12/26/14, 14:34, David Smith wrote: > Hello Friends, > I have two HP 3456A's that have the same "-3" fault in the "test" mode. Both > DVM's started exhibiting this same fault about the same time. I've > troubleshot one of the DVM's to a failure in the Isolation Logic > "Transmitter." I have no waveform at the output of A3T1. > Before I continue with troubleshooting I thought I'd ask a question of the > group. Is there a common mode failure of these DVM? Is there something in > particular or area that I should be looking at/for? > It's probably coincidental that they would both fail at about the same time > with the same -3 fault. > Your input is greatly appreciated. > Best regards, > > Dave - W6TE > _______________________________________________ > volt-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
