drjones
Member
I picked up a Joker Poker a few days ago with a dead CPU, no visible corrosion. I ran through all the troubleshooting I could find online to no avail. Managed to track down an untested CPU, thew it in there and the game showed the same symptoms. GI comes on, displays don't come on or strobe.
The second CPU I picked up had some corrosion cleaned off, it has seen better days. That said there is one difference I noticed between the two boards. On board #1 (Rev B) when testing the reset circuit using TC1 it goes right to +5 dcv, there is no initial -12 that climbs and stabilizes at +5 after a second or so. On the other board (Rev A) game is turned on and it shows -12 then up to +5 after about a second. Is this problematic for board #1? Is the initial -12 important or is it only important that it settles at +5? Many of the online guides recommend replacing components if there is a problem in the reset circuit; but the problem they allude to is always the voltage not getting to +5, so I'm unsure if the initial -12 is important.
I should also note (and I'm not sure if this is important or not) but some of the lighting that comes on is what I would guess to be CPU controlled lighting? Bonus lights, shoot again playfield light, etc. If the CPU is in fact toast, would those lights even illuminate?
The second CPU I picked up had some corrosion cleaned off, it has seen better days. That said there is one difference I noticed between the two boards. On board #1 (Rev B) when testing the reset circuit using TC1 it goes right to +5 dcv, there is no initial -12 that climbs and stabilizes at +5 after a second or so. On the other board (Rev A) game is turned on and it shows -12 then up to +5 after about a second. Is this problematic for board #1? Is the initial -12 important or is it only important that it settles at +5? Many of the online guides recommend replacing components if there is a problem in the reset circuit; but the problem they allude to is always the voltage not getting to +5, so I'm unsure if the initial -12 is important.
I should also note (and I'm not sure if this is important or not) but some of the lighting that comes on is what I would guess to be CPU controlled lighting? Bonus lights, shoot again playfield light, etc. If the CPU is in fact toast, would those lights even illuminate?
