Toplan hellfire with spotty sprites.
Figured it would be a ram issue but after slicing them all none showed up as bad.
No schematics but a few repair logs out there so at least knew where about to look.
Checked all the LS166s that convert the sprite data from the eproms into bitstreams but they were all good as well.
Previous experience is that LS157s have a habit of failing so looked at one near the sprite eproms:
Normally would have just sliced it but laptop wasn't turned on so I just scoped the inputs and outputs and found pin 5 was floating.
An inspection of the underside showed something had happened near on of the pads:
Checking continuity it appeared the trace was damaged,fixed it and sprites all good now.
Figured it would be a ram issue but after slicing them all none showed up as bad.
No schematics but a few repair logs out there so at least knew where about to look.
Checked all the LS166s that convert the sprite data from the eproms into bitstreams but they were all good as well.
Previous experience is that LS157s have a habit of failing so looked at one near the sprite eproms:
Normally would have just sliced it but laptop wasn't turned on so I just scoped the inputs and outputs and found pin 5 was floating.
An inspection of the underside showed something had happened near on of the pads:
Checking continuity it appeared the trace was damaged,fixed it and sprites all good now.
,
