Hi Dave, Over many years, I have bought several non-working 3458A DMMs from several sources, repaired/refurbish and resold them. Most needed a new A3 A/D converter board 03458-66503 due to the well-known drift issue. I maintain two such 3458As both on current Keysight service contracts with one on a multi-year calibration contract that I have calibrated yearly and use to keep my personal cal lab standards characterized.
Has your A3 board actually failed or does it just have excessive drift? If it has failed, what is the error code (maybe multiple codes)? I have always exchanged the failed 03458-66503 boards for a replacement 03458-66513 usually around $1300 exchange. Keysight now shows a 03458-66533 board as the replacement but offers no exchange and says instrument must be returned for repair??? A search for HP 03458-66503 shows a company offering a "tested" board for $899. Regards, Don Johnson Retired HP Engineer -----Original Message----- From: Dave McGuire <[email protected]> Sent: Monday, October 18, 2021 10:53 AM To: [email protected] Subject: [volt-nuts] new member, seeking 3458A advice Hi folks, I'm new to the list, but I think I'm acquainted with many of the people here. The time has come to get my 3458A repaired and calibrated. It's a middle-aged unit, built in 2000, and its ADC board has failed. My first inclination was to send it to Keysight, which would give me great confidence, but I understand there may be other options. I'm not made of money, but I am willing to pay for a trustworthy repair and calibration. I am well aware that whatever route I end up taking will not be cheap. I figured this list would be the best place to request advice. What would volt-nuts do? Thanks, -Dave -- Dave McGuire McGuire Scientific Services, LLC New Kensington, PA _______________________________________________ volt-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
