Fried 3.5mm jack

I have been trying to add an auxiliary jack to my head unit in the Volvo. The reason being that it’s a old Amplitude Modulation type radio. As such I can’t listen to anything that I want to, only FiveLive and some foreign channels. So I borrowed an oscilloscope and was doing some testing, when the some smoke came out of the wires connecting my phone to the head unit, the wires were an old set of head phones, with the ear bud cut off and wires tinned for a good connection.
The phone repair guy remarked that he was unable to fix my phone and that he was surprised that my phone seek worked at all because  the mother board was actually charcoal in that corner! All the components were fried.