Not a game I'd ever heard of and no love for it on ebay recently where it was listed as faulty/non-working for a tenner !!
Turned up in fantastic condition, yeah someone's put a big sticker on and written on it but the actual 3 layer pcb looked like it had come out of the factory last week !
(photo doesn't do it justice)
Fired up to a couple of issues ... graphics not right and no sound ....
Despite the solder side of all 3 layers of pcb looking crispy new, the bottom pcb did have a number of longer than normal component legs coming through which were bent over quite close to others. Did a full inspection under the magnifier and straightened out a lot of legs, the worst of which were in the sound corner of the pcb. This maintenance alone brought back full sound to the game on next power up
but made no difference to graphics
Looking at the screen I decided it was a issue most likely confined to the text/character layer only. This layer (which in this case includes the outline of the player) obviously has the highest priority and displays over the sprites and backgrounds which seemed to be ok under all the wrong text and random symbols on the screen...
Hunted down the ROM's for the text layer, these are labelled 7 & 8 and are hiding just under the top pcb.
Scoped the ROM address lines and pin 4 (A6) signal was stuck (high or low can't remember) while all others were toggling, as were /OE and /CE. Traced the A6 signal on pin 4 back (using the schematics) to a LS273 (output pin 6) just above the ROMs ... signal also stuck here.... checked all other pins of the LS273 and all carrying healthy signals !
Looking like a bad LS273 then, piggybacked a working one on the top and got some improvements ... not perfect but a lot more readable ....
Enough evidence to change that chip out and as expected it failed out of circuit test and a replacement went in ....
And this fixed the text layer completely .... and game is 100% working ....
Cleaned up the PCB, not played it much but seems ok, a bit operation wolf ish, not sure if there's any love out there for it though ??
Turned up in fantastic condition, yeah someone's put a big sticker on and written on it but the actual 3 layer pcb looked like it had come out of the factory last week !
(photo doesn't do it justice)
Fired up to a couple of issues ... graphics not right and no sound ....
Despite the solder side of all 3 layers of pcb looking crispy new, the bottom pcb did have a number of longer than normal component legs coming through which were bent over quite close to others. Did a full inspection under the magnifier and straightened out a lot of legs, the worst of which were in the sound corner of the pcb. This maintenance alone brought back full sound to the game on next power up
but made no difference to graphics Looking at the screen I decided it was a issue most likely confined to the text/character layer only. This layer (which in this case includes the outline of the player) obviously has the highest priority and displays over the sprites and backgrounds which seemed to be ok under all the wrong text and random symbols on the screen...
Hunted down the ROM's for the text layer, these are labelled 7 & 8 and are hiding just under the top pcb.
Scoped the ROM address lines and pin 4 (A6) signal was stuck (high or low can't remember) while all others were toggling, as were /OE and /CE. Traced the A6 signal on pin 4 back (using the schematics) to a LS273 (output pin 6) just above the ROMs ... signal also stuck here.... checked all other pins of the LS273 and all carrying healthy signals !
Looking like a bad LS273 then, piggybacked a working one on the top and got some improvements ... not perfect but a lot more readable ....
Enough evidence to change that chip out and as expected it failed out of circuit test and a replacement went in ....
And this fixed the text layer completely .... and game is 100% working ....
Cleaned up the PCB, not played it much but seems ok, a bit operation wolf ish, not sure if there's any love out there for it though ??
