The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

I have a cobra 142GTL, it's dead. how do I test the power transformer.
and what is the voltage coming out. thank you

hello,,is the fuse blown,and does it blown the fuse instantly when you power it up..you might have a rectifier diode shorted,on the power supply board..some have four diodes in series,and some radios just have one bridge rectifier..square black chip with four legs attached to power supply board.check these for short circuit..and as far a voltages you should have 12 volts at the power supply board,check this voltage at the red wire off supply board to red lead of volt meter,,black lead of volt meter to pc board ground..........................good luck ...............ramblingman

A common fault used to be TR401 (2SD188) going open circiuit, you can check this by hookup an PSU to the power socket on the back of the radio and switching it to DC from AC.

Thanks, fuse is good, done the power test 00.2 or 00.25 if i did it right. im new at this stuff.
put dc current to it, and it came on. could it be the power transformer or the other

Switch your test meter to AC and test the 2 wires coming out of the power transformer there should be about 15 to 20 volts AC. Let us know how you get on.

Hey thanks alot rick, I got 117.9 going in and nothing coming out.
( power transformer bad ) if so where would be a good place to get one. Thanks again rick, just trying to save a buck