It did work until I put everything back together. Now it is back with the same HARDWARE ERROR. I'm going to have to do a full tear down and take a very hard look at everything.
The seller told me that this was his personal bench meter for the last four years and that it was working 100% before he shipped it. I have no reason to doubt that. I suspect that something got jarred in shipping and is either loose or shorted. I hope it isn't a cracked trace. I read the CALNUM and it was 34. There are remnants of anti-tamper labels on some case screws from these guys: http://www.ssclabdivision.com. So, it has perhaps been calibrated/adjusted at least once since manufacture. I downloaded the Scope of Accreditation document for the above lab. Am I interpreting things incorrectly, or do the uncertainties for DC voltage source (in particular) look large? One very odd thing that I noticed when it was open was the remnants of a wire that had been tack soldered to what looks like a voltage regulator. See the picture here: https://dl.dropboxusercontent.com/u/19599147/HP%203457A%20Oddity.jpg Joe Gray W5JG On Thu, Aug 22, 2013 at 1:31 PM, Joseph Gray <[email protected]> wrote: > I got the OK to open the 3457A. I didn't see anything that was obviously > loose or broken. I reseated all connectors and also the socketed ROM. It > now powers up and passes self test (at least twice so far). I did all this > over lunch, so tonight I will be taking an even closer look at things. > > While I had it open, I looked it over a bit. All the chips are dated late > 1991 or early 1992. The old optocoupler has been replaced by two chips that > span the slot in the board. > > The battery looks like it is probably original. The solder connections > don't look re-done. The battery is a Panasonic BR-2/3AE2SP. The tab on one > end has one point, the other end has two. Mouser sells these for $5.24. > > Joe Gray > W5JG > > > > On Wed, Aug 21, 2013 at 5:34 PM, Joseph Gray <[email protected]> wrote: > >> Boy, I have the worst of luck. I think Murphy follows me around. I won't >> bore you with the details about my recently dropped by Fedex service >> monitor and major repair cost. >> >> The 3457A arrived. Other than missing feet, it looked in decent >> condition. I powered it up and that is when things went wrong. >> >> The first several times, on power up, I got the Address display and the >> beep, but instead of going to DCV, it displayed PASSED, with an occasional >> FAILED. It would do this seemingly forever. >> >> Once, it powered up normally, then froze. Another time, it powered up >> normally and I managed to read the error code (1 - Hardware error) and the >> auxilliarly error (1 - Isolation error durring normal operation). >> >> Later, it would power up and immediately display FAILED. At this time, I >> happened to lift the front of the cabinet and saw that FAILED and PASSED >> would randomly alternate on the display. Something is definitely loose. >> >> I would have already opened the DMM up, except the seller applied >> anti-tamper labels to the case screws (I have a 30 day warranty). I have >> sent all of this information to the seller. Hopefully, he will authorize me >> to open the case and see what is what. Otherwise, I have no choice but to >> return the DMM. >> >> Joe Gray >> W5JG >> >> > _______________________________________________ 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.
