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cobra 29 wx nw st

randl

New Member
Jun 14, 2017
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I received a cobra 29 with burnt out finals. I put a mosfet kit in it. The IC4 audio chip gets very hot. I replaced the chip and it still gets hot. I checked the solder joints and they look good. I don't know if the IC4 is getting hot from what I did or from the previous damage. Any ideas on where to go next?? The IC4 chip has 12.6 volts across the the terminals. Is this to high?//
 

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You replaced the IC, did you put the thermo-grease on it before mounting it?

You need a copy of this:
http://www.cbtricks.com/radios/cobr..._st/graphics/29ltd-st_29wx-st_sm_pg1_pg11.pdf

http://www.cbtricks.com/radios/cobr...st/graphics/29ltd-st_29wx-st_sm_pg12_pg34.pdf

it has the voltage charts in the Second link

And he is some more 29 porn for you...

http://www.cbtricks.com/radios/cobra/29ltd_29ltd_st_29wx_st/graphics/cobra_29ltdwx-st_29ltd_sch.pdf
You replaced the IC, did you put the thermo-grease on it before mounting it?

You need a copy of this:
http://www.cbtricks.com/radios/cobr..._st/graphics/29ltd-st_29wx-st_sm_pg1_pg11.pdf

http://www.cbtricks.com/radios/cobr...st/graphics/29ltd-st_29wx-st_sm_pg12_pg34.pdf

it has the voltage charts in the Second link

And he is some more 29 porn for you...

http://www.cbtricks.com/radios/cobra/29ltd_29ltd_st_29wx_st/graphics/cobra_29ltdwx-st_29ltd_sch.pdf
Yes, I did put the thermo grease on them. Thanks for the links!!
 
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This is the first radio I am working on. It was a freebee. It was not working when I got it.
 
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Yes, I am determined.
It is frustrating. I found out that with the different models of cobra 29 that the wire diagrams and audio chips are different. I am having a hard time finding the right wire diagram for my model. Unfortunately, I don't have to much spare time. But, I will keep posting what I find.
 
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Thanks very much! It is very helpful.
The one thing I have not been able to figure out yet is where it shows capacitor C42. On my radio it is actually C41. And where the scamatics show C44 mine is C39 no matter what year the radio is.
I will keep posting. This is a slow works in progress for me.
 
i know this was a long time ago and CB tips and tricks is down and none of the links work but mine is doing the exact same thing but I didnt change with a mosfet maybe someone else did???? any information would be a great help thanks!
 
Yes no RX/TX and audio chip gets hot

I temporarily have the meter out had to stick it in a different radio so I haven’t been messing with it lately
 

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