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HP Forum Archive 06

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CRT of HP 9100
Message #1 Posted by Dr. Jens Kirchhoff on 16 Oct 2001, 4:52 a.m.

Dear HP-friends, I need a real help: Who knows a source to get a CRT for the 9100, which was damaged on transport ? New, new old stock, rebuilt ??? Thank you for every glimpse of hint. JENS / GERMANY

Re: CRT of HP 9100
Message #2 Posted by Tony Duell (UK) on 16 Oct 2001, 2:26 p.m.,
in response to message #1 by Dr. Jens Kirchhoff

If you find a source, let me know as well, please. I know a couple of people who are looking for replacement HP9100 CRTs. I can't help with a source. AFAIK the CRT was custom-made for the 9100. It's similar to a 'scope tube (electrostatic deflection plates for both directions), but it's short for its screen size -- that it to say the deflection angle is larger than that of a 'scope. You might be able to modify the HP9100's electronics to drive a more normal 'scope CRT (something like a 3BP1) but the replacement CRT is not going to fit in the 9100's case :-( What is wrong with the existing CRT? Be warned that if the glass support rods inside have broken, then it's possible the deflection plates have shorted to the anode. If this happens, then it generally blows transistors on the deflection board, diodes on the gating board, and if you are unlucky transsitors on one of the flip-flop boards. If the machine works apart from the CRT (try STOP STOP 1 CHS SQRT (to force an error) -- the CPU is working if the error lamp turns on) then the damage is likely to be confined to the deflection board and maybe the odd diode on the gating board.

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