I've had this PCB for a very long time, in fact i won it on ebay as an "untested" PCB about 20 years ago, back before the schematics were available.
I attempted to repair this about 15 years ago but without schematics and no visible traces I had no idea where to look, I did Romident it back then and discovered it was actually an original Japanese version Makaimura rather than regular Ghost & Goblins, i did find way back that ROM1 & ROM2 would not romident and these were replaced.
Anyway fast forward over a decade and being in the mood while i am fixing a batch of Pacman PCB's I thought i'd give it another go, with the schems.
Symptons.
The board would as best as I can describe it "Chirp" - flashing constantly between a white screen and a screen full of garbage.
Repair
I started looking at the CPU circuit, and confirmed data and address lines between the CPU & Roms were pulsing, i originally thought the board was reseting but the reset line was working as normal, high to low after boot (or the other way around) - activity on the Clock was chirping so I traced this all the way back to the LS04 @ 3N again a similar chirp of high pulse was present so i removed it and it tested OK in the IC tester, I then spent probably a day or two tracking this chirp all the way through the circuit back to the CPU and couldnt see any problems, that lead me to look further into the CPU and which lines were also chirping, the IRQ on Pin 3 was constantly high, this was normal under operation of the game, the only other pin that was chirping was Pin 36 MRDY - this I traced through the 367 at 10J - onto 7K & 6F and finally onto pin 2 of 3H where i found the input on Pin 5 (AB10 was chirping) - back to the CPU Circuit...
AB10 was output on the 74LS245 on pin 13 & this is where the chirping stopped, nothing in or out on any other pins was chirping away..
when i took a closer look on this IC it was aparent that it had see the end of a soldering iron in the past but it was a clean repair or "reflow" just the presence of some flux residue.
Whipped it out and tested it on the IC and it failed, so a quick socket and fresh working 245 and powered it up to.... an upsidedown test screen.
Both of these are controlled by the DIP's so normal screen & test mode off and the PCB Boots again for the first time in 2 decades.
Will add some pics later
I attempted to repair this about 15 years ago but without schematics and no visible traces I had no idea where to look, I did Romident it back then and discovered it was actually an original Japanese version Makaimura rather than regular Ghost & Goblins, i did find way back that ROM1 & ROM2 would not romident and these were replaced.
Anyway fast forward over a decade and being in the mood while i am fixing a batch of Pacman PCB's I thought i'd give it another go, with the schems.
Symptons.
The board would as best as I can describe it "Chirp" - flashing constantly between a white screen and a screen full of garbage.
Repair
I started looking at the CPU circuit, and confirmed data and address lines between the CPU & Roms were pulsing, i originally thought the board was reseting but the reset line was working as normal, high to low after boot (or the other way around) - activity on the Clock was chirping so I traced this all the way back to the LS04 @ 3N again a similar chirp of high pulse was present so i removed it and it tested OK in the IC tester, I then spent probably a day or two tracking this chirp all the way through the circuit back to the CPU and couldnt see any problems, that lead me to look further into the CPU and which lines were also chirping, the IRQ on Pin 3 was constantly high, this was normal under operation of the game, the only other pin that was chirping was Pin 36 MRDY - this I traced through the 367 at 10J - onto 7K & 6F and finally onto pin 2 of 3H where i found the input on Pin 5 (AB10 was chirping) - back to the CPU Circuit...
AB10 was output on the 74LS245 on pin 13 & this is where the chirping stopped, nothing in or out on any other pins was chirping away..
when i took a closer look on this IC it was aparent that it had see the end of a soldering iron in the past but it was a clean repair or "reflow" just the presence of some flux residue.
Whipped it out and tested it on the IC and it failed, so a quick socket and fresh working 245 and powered it up to.... an upsidedown test screen.
Both of these are controlled by the DIP's so normal screen & test mode off and the PCB Boots again for the first time in 2 decades.
Will add some pics later