IIRC the P6 had an odd ball pass regulator. Both a transistor
& an STR. A small cap would open & a resistor would burn.
I dont have a manual & my memory is not there.
So attack the regulator & look for the resistor. IIRC it was
near a heat sink.
BTW careful not to run it too long or the HOT may short again.
73 Zeno