Get a PLCC extraction tool and then look at this page:
Looks like a defective MPU board to me.
Extraneous solder balls under a surface mounted PLCC socket is never a good thing. Doesn't take much to dislodge a solder ball and cause random shorts - such as inserting PLCC IC into socket or reseating it.
Based on glaring issues with that board, IC nearly pulled back, solder balls under PLCC socket and solder bridges, I have sincere doubts that this board has ever been inspected or tested. There's no excuse for this type of shoddy workmanship.
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