Troubleshooting dead Duex5

selkovjr

I fried my DuetWifi by shorting something. I have no idea what I have touched, but I heard a faint popping sound and it stopped working entirely. The damage I can see is a pool of molten plastic and a breakdown crater in U2.
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I replaced the board with a Duet 2 Wifi and now the Duex5 does not register. I can't find any obvious damage in it and I have not touched it while replacing the Duet. The two endstop lights on the Duex5 are on, and that is all I can see. Is there a way to find out whether it is salvageable?

dc42

So the 3.3V regulator fried. This is caused by a short between a component connected to VIN and the +5V rail or the +3.3V rail. Typically this results in over voltage on the +3.3V rail, damaging components powered from it.

So my guess is that the I2C bus expander on the DueX has failed. Replacing that chip may salvage the DueX. Or not, if additional components on it have been damaged.