Usually cause the power surge protect diode has been destroyed. That's it's job. Sometimes the reverse power problem will travel beyond the diode and burn up a trace on the solder side of the board.
Solder a bit of wire to bridge the burnt spot. Rosin core solder. Replace the diode using a suitable size / make of diode. Make a drawing of the location of the silver band on the diode. Called the cathode side. Usually on the board drawn as line, l next to a triangle -l< Scrap electronics should have some you can use. Diode is close to where the power is entering the radio by a largish capicator.
War diese Antwort hilfreich?
It would help us diagnose this if you could share a photo or a wiring diagram of what you're trying.
von Kyle Wiens
I hook up my cobra 29 classic with a 3 prong in line fuse to my Volvo semi truck and it keeps blowing fuses the diode is just fine
von Adam Post