Friend of mine in Florida dug out an old HP Infinium 54845A from storage that he needs to use for some RF work he is doing. When he first turned it on, it indicated the HDD was dead. Since he does not have much experience with the software (or digital) side of life, he asked me for some help. After looking around I found the answers here on EEVblog (what a great resource!) and suggested to him that it might be easier for him to ship it up to me and let me replace the HDD and install the software. I have most of the old equipment needed and scrounged the rest, and ordered a new HDD for the Infinium.
This is where things took a bad bend. The scope arrived with the issues above, but only about 1 out of 4 power-ups caused it to actually light up the screen and (attempt) to boot. I assumed he just glanced over that issue, and I proceeded to test the Windows 95 boot disk I created. That is when the power-up went from 1 out of 4 to never. The power supply fans come up, and the keyboard lights momentarily flash, but nothing else. Seeing that the motherboard has no speaker, I dug one out and plugged it in. According to the AMI BIOS docs I could find, the 8 beeps I now get indicates a missing video. My friend indicates that the display always came on when he pressed the power button, so it seems like some kind of progressing time bomb :-(
I've tried re-seating everything including the HP custom "display" board, and instead it has gotten worse where it won't even beep if the display card is installed. Of course, without the card it still complains about no video card :-)
I have a PDF of the Agilent Model 54835A/45A/46A Oscilloscope Service Guide, and I see where they use a ISA POST card and also details on checking the power supply voltages on the acquisition board. I'm also going to track down an old ISA video card to try. Has to be one lying around in those boxes...
!! Now the question !! I will pursue the provided diagnostic steps, but to what end? I see various Infinium ISA cards listed on eBay. How model specific are these cards? Can I use a display card from a different model if testing indicates a display card problem? Just a quick scan of the cards tell me that it is unlikely I will be doing a low-level parts swap on the card.
Thanks for any advice!
Deron