I’m glad to hear that the Duo didn’t get fried when the power supply went.
From what I’ve seen on YouTube tear downs, the power supply is glued together and would be hard to disassemble and reassemble cleanly, but I don’t have any firsthand experience. A loud ‘pop’ sounds to me like a capacitor blowing up. There are a couple of large caps inside the supply that might need to be replaced. I don’t know if any other damage might have been done when the ‘pop’ happened.
I think this video is the one I saw that showed the power supply tear down:
Edit: two other things worth mentioning
1. Last time I looked, Duo power supplies weren’t too hard to find on eBay at reasonable prices. Obviously they’re also old, and might suffer the same failure that yours did, but buying a replacement might be a better option than trying to salvage the dead one.
2. Duos have several large electrolytic capacitors on the logic board in their power supply circuitry, which handle the input 24V and ~12-14V battery charging. Over time these caps leak, and the leaked ‘goo’ is conductive, which can result in these high voltages being conducted to other components on the logic board. Most components on the board are expecting ~5V, so this failure can be catastrophic. There’s an old thread about this risk:
And another thread about restoring a 230:
You’d want to make sure that the caps on your board match the values shown in those posts, just in case there’s an error in the guides.
