I'd be looking at a dead PSU, so I would try another. What are you using as the powersupply. all the problems before may be accounted for by faulty power and slight change from the arc just took it (PSU) over the edge to protect itself/destroy itself. I have been using the official PSU (KSA-15E-051...

Finally was able to test with a multimeter, and here are the results. Pandemic made it difficult to find a new apartment, let alone get my hands on a multimeter. Voltage measured between TP1 and TP2 was 0V, whereas I understand it should be between 4.75V and 5.25V. Voltage measured between pin 9 (gr...

No perceptible heat at all, as far as I can tell. I'll borrow my friend's multimeter on Monday or Tuesday and report back on the voltages.

Btw, the laptop was off at the time and has no battery (removed because it's old and just a dead weight).

My brother gave me an RPi4 (4GB) with the official power supply recently as a gift, and it died after a few weeks of use. I'm hoping I might be able to resurrect it, or at least learn something trying. Pre-death, the pi would occasionally hang (pressing num lock wouldn't toggle num lock light, Pi in...