Dec 142016
Although issues were different in these two repairs (well, quick fix more than repair), the cause was the same.
Here’s the first board, a Super Spacefortress Macross :
Board had issue on some backgrounds which showed colored blocks :
A visual inspection revealed a lift pin on a QFP custom ASIC:
Reflowing the pin fixed the game:
Second PCB was a DoDonPachi :
with wrong music and sound FXs:
Also here the culprit was a lilfed pin (an address line, specifically) of the Yamaha YMZ280B-F (PCM/ADMPCM decoder)
Promptly fixed and sound 100% restored :
So, the bottom line is that you must always keep attention when you troubleshoot PCBs that use SMT devices, always check these for first…