Hi Alan,

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I have seen that video before. The meter gives a BEEP and then all green rectangles on the screen plus all the other function below are illuminated, probably as a check to confirm that all the display characters light up.

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Mine doesn’t get past the first rectangle. It just sits there and blinks.

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Also, I just noticed that mine has an Agilent front panel, yet the serial number starts with 2823A… indicating a build date of 1988. I think someone has spent significant $$$ on this machine, probably with Agilent, before I acquired it.

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Thank you for the good advice about the ROM and NVRAM chips. I have an EPROM reader/burner (GTek 9000HV) that is supposed to be capable of reading the Dallas chips, and I will get to them in due course. Unfortunately they are not socketed, so they will need to be carefully unsoldered. I will put in high quality sockets if I have to go down this road.

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I will first try resocketing the EPROM chips to see if that helps. If not, I will try reading the EPROM chips in the GTek to see what they contain. They all appear to have new labels with what I think may be Agilent part numbers. One of the labels looks like it may have been lifted in one corner (top right chip, bottom left corner of label is crinkled). Hmmm…

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I don’t make any progress, I will download the binaries for Rev 9, buy a new set of EPROM chips and burn them in.

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Thanks also for the battery issues/calibration blog link.

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I do not plan to have this meter calibrated to the point where it is NIST traceable. I want to use it for comparison measurements with repeatable 8.5 digit resolution. I have an HP3245A Universal Source (no longer in cal), and if calibration of the 3458A turns out to be necessary, I will use the 3245A as a voltage reference to calibrate it. I also recently purchased an ?on ePay, and I am hoping that it will agree closely with the 3245A.

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I do most of my lab work with 8753X VNAs. I have several 8753E’s as well as a C and an A, and I use them for a range of testing tasks, including in conjunction with an 8-port HP87050 coax switch and some very expensive BH baluns to test balanced pair data cables and components for clients. I have written a lot of software in FREE PASCAL to drive the GPIB port in order to automate the testing. I use an 82335 ISA GPIB card in an old PC running on DOS. Works like a dream. I have also written GPIB software to drive other HP test equipment. So talking to the 3458A will be no problem, once I get it to wake up!

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Thanks again for all your help Alan.

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Cheers,

George

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