16 Mar
2006
16 Mar
'06
3:21 p.m.
I have an HP 9825A with Opt 2 (24K RAM) which does not display the
lazy T symbol on power up (dark display on power on).
Virtually all faults in HP desktops give no display :-(
I have checked the PSU voltages and they are OK and have carried out
the obvious tests to see if the problem is a dead display ([RESET]
spc [EXECUTE] [RESET] beep [EXECUTE]) but nothing happens.
Oh, the fan works fine, there are lights inside the tape drive slot
and when I press the CAPS key the CAPS-LOCK LED turns on (and goes off if
I press CAPS again).
I would like to remove the second memory board (16K) just to be sure
that its not a prob with it. The manual suggests that a dummy board
was installed in the place of the 2nd memory board. Does that mean
that the machine cannot work with one memory board?
The machine should be fine with just one memory board, but it must be
addressed correctly (I forget if it needs to be at the top or bottom of
thr address space).
Also will I get a display with the tape board disconnected?
Yes.
Thanks
**vp
PS I have the 9825A Service manual, but this simply tells you how to
disassemble the machine. In fact the troubleshooting flowchart essentially
tells me that anything could be at fault.
I assume you also haev schematics from http://www.hpmuseum.net/
-tony