Hi
I have an HP 4195Aa that I did not use for sometime. I switched it on yesterday and the screen remained black, with alarms on the processing board A6. On the front, only the LED ext ref and lock are on. These symptoms seem to be caused by a failure of EPROMs in A6, according to some.
On the A6 board, there is a 2.4 V NiCad battery. It seems that when this battery fails, the board remains in RESET status and the unit cannot start.
When I leave the unit on for some time, it starts when I switch it off and on. So the issue seems to be related to temperature. When I remove the A6 board, cool it and put it back in the unit, it does not work. The unit works again after it has been on for a while. However, there is no signal trace.
Is there someone with a similar experience. How to get the data for the EPROM ?
Aba