PC Post Card
PC post card is a diagnostic test card to troubleshoot cpu motherboard. I used to repair and troubleshoot cpu motherboard many years back when i was starting out in the pc repair line. The manufacturer supplied me with a pc post card and i plugged it in the motherboard slot. When i power it “on” i could see numbers running (counting) shown by the LED display at the card itself. Assuming it stopped at 40 then you have to refer to the manual book to seacrh for what’s 40 mean.
If the 40 explained in the manual was Ram then your concentration would be in the Ram are. This save your time especially when a motherboard have the symptom of no display and you do not know where to begin to check. Surf the net for the pc post card and i’m sure lots of companies offering many type of diagnostic test cards. Get one if you are in the CPU motherboard repair line.