The fan was a bad battery cable, but otherwise I managed to get Logic to restart, so the problem is related to the WiFi card. I removed all the capacitors around the chip, hoping one of them was broken. In reality, it's PP3V3_S2_WLBT_INS that's shorted. I read this article a bit:
https://logi.wiki/index.php/M1_MacBo...I_Module_death
and I'm in exactly the same situation. I was thinking of isolating all the PP3V3_S2_WLBT_INS lines and re-soldering the chip, but I don't know if that makes sense.
I was thinking, and I think it's crazy, about installing a WiFi dongle inside the...

sorry