Cobra 29 classic

[Rick brown]

I don't work on CB's to much but I have done a few mods to them,my friend gave me a 2011 cobra 29 ltd classic,the audio chip gets extremely hot,does power up,if you hook up to the pa and try to use it as soon as you flip the switch it has a loud buzzing noise from the speaker,please help.

 

[sonoma]

check the electro caps at the audio chip to see if one is bad. C48 I think is right there. check it 1st

 

[Rick brown]

Thank you for your help.

 

[Rick brown]

I checked all the caps and they check out good,can tr 13 be bad causing my problem?

 

[Rick brown]

I used a Esr meter that I borrowed from a friend and all caps checked ok.

 

[sonoma]

check to make sure the audio chip is not shorted to the case . does the noise only happen in pa mode. use the ohm meter to make sure and see if it is snug to the case whith heat sync compound on it. there is a insulator between it and the case to prevent it from shorting.

 

[Rick brown]

I checked the insulator for case ground all ok, I changed the audio chip from another cb that I had and double checked the insulator. Hooked up and turned on then the audio chip popped and cracked the side closest to the front, and then nothing. I have to go to my daughters ball game,I will work on it again tomorrow,thanks again for your help.

 

[Rick brown]

I changed the audio chip again and double checked everything,my fault,left a jumper unsoidered,now pa don't buzz real fuzzy,still no transmit or recieve.