Help identifying source of corrosion (details in description)
Hi guys. I am very new to the electrical repair scene and need advice from someone more experienced.
I am currently repairing a Yamaha Electone B-75 electric organ. It is a very old organ from 1973 so the components are obviously prone to failing. It was working when i bought it, but as soon as i got it home and plugged it in a capacitor on the power supply poped and blew a fuse in the process. Because of this i am unable to test the rest of the circuits until the fuse gets delivered.
While visualy inspecting the rest of the circuits i noticed this localized patch of corrosion near one end of this IC and on two adjacent diodes. My instinct was that an electrolytic capacitor had blown, but the capacitors in the area (shown in picture 3, 4, and 5)show no signs of leaking and have no corrosion on their leads. This board is one sided, there aren't any components beneath it, and it is shielded from the restof the boards but a metalized paper shield so it can't be caused buy a component elsewhere. I have provided the IC diagram incase that helps.
I hope it isn't caused by a failed IC because these chips are really hard to find now days.
If anyone with more experience could help me out it would be greatly appreciated!
Edit: additional details.