John, Can you give us more information? Serial number, Rev. number, CALNUM? How much to invest will be determined by age and other condition.
It doesn't sound like a simple CALRAM issue but changing the CALRAM is relatively easy. I removed all three DALLAS chips in mine and installed sockets. The CALRAM can be read with a chip programmer and the data written to a new DALLAS chip. I would also call Gary Bierman at the Loveland Cal Lab and have a long talk with him. He has a lot of insight into these meters and generally prefers to do a component level repair rather than an assembly level repair. The charge sounds like their standard repair charge, no matter what the problem is, and includes a 'fresh calibration' along with a warranty, a year I think, but Gary will be able to answer that question. Also, once you get the meter calibrated by Agilent (and thus prove it is functioning normally) it will be eligible for their 'repair agreement' which is $178.68 per year. I would consider buying a 5 year agreement after the repair. Good luck. Joe -----Original Message----- From: volt-nuts-boun...@febo.com [mailto:volt-nuts-boun...@febo.com] On Behalf Of John Phillips Sent: Tuesday, September 17, 2013 3:36 PM To: Discussion of precise voltage measurement Subject: [volt-nuts] HP 3458A repair. Hi, I have a 3458A that we sent to Agilent for calibration which it failed. Before we sent it we calibrated it and it looked good to us. The infor. we revived led us to believe that the cal memory may have caused the failure. We ask that it be sent buck to us and paid half the cal charges (about $800) insted of the $2660.64 they wanted to repair it. We were just going to repalce the ram in try again. When we got the meter back it came with befor and afer data Like before 10 volts read 9.9999957 and after it read 10.00009 so they did something or the meter drifted that much. The problem is 0.1 volt and 1.0 volts failed at 8 and 10 MHz but passed at 4 MHz. 4MHZ 0.1 volt reads 0.097251 Lower Limit is 0.095930 PASSED 8MHZ 0.1 volt reads 0.085712 Lower Limit is 0.0959 2 0 FAILED 10MHZ 0.1 volt reads 0.75569 Lower Limit is 0.084900 FAILED 4MHZ 1 volt reads 0.97272 Lower Limit is 0.95930 PASSED 8MHZ 1 volt reads 0.86389 Lower Limit is 0.95920 FAILED 10MHZ 1 volt reads 0.73514 Lower Limit is 0.84900 FAILED The AC after readings are the same. I do not see how AC after could be that identical even if they did not try to calibrate it. Did they just copy the before data and call it after data? My best guess is that if the 4 MHz is in and the higher frequencies are not the meter requires some kind of mechanical adjustment to get the frequency response withing spec or the AC board needs to be repaid. Are they charging a standard repair charge to do a calibration? I do not see changing the memory to fix this. Where would you go from here if this was your meter? -- John Phillips _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.