A Mercedes-Benz key fob needed repairing after its integrated circuit (IC) became too hot, causing its internal wiring to come loose.
Repair work involved grinding back the IC’s epoxy surface to reconnect the circuit, which is particularly fiddly when repairing ICs that contain encryption secrets.
Responding to comments, the SOC in a key fob becoming hot enough to melt bond wires is most likely a manufacturing defect, and the cost of a replacement key fob and programming is approximately $800.
Also, never throw away your last working key fob, as it can cost upwards of $4500 to replace an ECU if you lose all working keys.
