• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

Macintosh SE PSU 820-0385-A R309 Value


New member
I am trying to repair a 820-0385-A PSU. However, the casing for resistor R309 is gone and the resistor is a dead short. Does anyone know what the value of this resistor is? Also, what is the black mold-like corrosion on the bottom of the PCB?


Well-known member


New member
Thanks for the link, I saw this post but the answer wasn't definite. I just ordered the caps for them and was lucky enough to score a Sony power supply from eBay, probably end up using that anyway.