Dead HP-9825A

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). 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? Also will I get a display with the tape board disconnected? 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.