Question about Cobra 29 WX NW ST 40-Channels Base CB Radio

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No power to radio wont even turn on

The inline fuse is not blown but, previously would blow. wont turn on and is plugged in/

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The most likely thing is what we techs call revers polarity. this means that the customer accedently hook up the power in reverse. this happens more often then not. The fix for this is to replace the 1 amp diode that goes between the negative and positive power input on the board. the Diode number is a 1N4007 or any 1amp silicone diode. You will also see that once Blown diode is cut the radio will come back on. this does not mean the radio is fixed what this means is that the shorted diode has been removed from the circuit. which also means the radio has nom protection until the diode is replaced.

Patrick Patterson N5SLI

Posted on Jun 02, 2009

  • cgarcia_6307 Sep 09, 2011

    es buena tu informacion yo no soy electronico pero si es entendible gracias



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Check the inline power fuse first/or replace it! If that does'nt work then next make sure the radio is in the operating possition on the switches labeled>cb/pa< to cb mode. If this does'nt work then you may have a wire from your power plug inside the radio broken loose or a blown diode. If in fact the wire is connected inside the radio the diode would be my next guess. This happens when the polarity of the radio is reversed(hooked up backwards). This can be fixed relativley easy at your local radio shop for about 30$. Good Luck.

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