Re: Any 9100 owners out there? Message #11 Posted by Tony Duell on 22 Oct 2011, 4:04 a.m., in response to message #7 by Eric v d Wateren
I was watching it on E-bay, I didn't intend to buy it, but I wanted to see how much it went for. Way more than I could ever afford....
The CRT is impossible to find now. It was a custom part for this machine, it's an electrostatically-deflected one with a larger than normal deflection angle (I suspect this leads to some non-linearity in the display, but this doesn't matter for displaying digits).
Worse than that, the electrodes in the electron gun are supported by fragile glass rods. If these break (due to rough handling), it not only ruins the CRT but if the electrodes then short together it can apply high voltages to the logic side of the machine, taking out transistors and diodes all over the processor section. Ouch.
The HP service manual is mostly a boardswapper guide, but it's worth reading nonetheless. It has some information on the PSU and CRT circuitry, and a warning to remove and inspect the CRT if you suspect the machine may have thrown about. I do it anyway, but then I am not afraid of taking thing apart ;-)
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