My HP 3325A suddenly went black, and will not respond to pressed keys.
The cpu seems to be running but the only clock on the front panel interface I can see is the LWKD that clocks 7-segment data. The other two clocks are permanently high. They come from two different LS138's so I find it hard to believe both chips failed.
Is there any way the the cpu can programatically decide to not clock the front panel?
The power supplies are OK.
Can anyone help me with some idea of how to proceed?
Thanks, Anders J