cobra 29 problems

[minitrucker]

i got a cobra 29 nightwatch for free.......because the guy who had it hooked the power and ground up backwards and fried it !!! .....can i expect to pay lots too get this fixed ?

 

[mopar2ya]

Maybe. It depends on the extent of the damage. Sometimes all that gets smoked is the reverse polarity diode. If that is the case it is an easy fix. You can check it out if you are brave. All you will have to do is cut the diode shown in the picture below and power up the radio and see if it works.

If you have an ohm meter, after you cut the diode, check for continuity from the negative lead to the positive lead at the power plug. If a simple diode test shows short or very low resistance, don't power up the radio. Take it to a shop. If it shows high resistance, continue.

Please, use a fused power wire. A 3 amp fuse is plenty. You may blow that fuse if you try and transmit with it if it is modified, but 3 amps will help prevent further damage.

Please, if you do this, don't accidentally hook it up backwards testing it or you will have some serious repairs if you don't already.

If you find that this is the only problem, acquire a 1n4003 or similar diode from radio shack and replace the one that is destroyed with it. If you only cut the existing one, and never replace it, you will have eliminated the reverse polarity protection and the next time it happens the damage will be greater.

One other thing. I like to replace the diode with one that will provide more protection. A 6 amp diode will protect the radio and all that will happen will be a blown fuse if the fuse is less than 6 amps. Much easier to fix. I install the new bigger diode right on the power plug like Galaxy and the exports do.

Good luck,

Mopar

 

[minitrucker]

i opened it up and the wire that hooks the ground to the board is burned.....the shielding is melted

 

[mopar2ya]

Not a good sign, but try what I told you. The diode you need to cut is the one with the red arrow pointing to it in my previous post.

Mopar

 

[SkipJunky]

i opened it up and the wire that hooks the ground to the board is burned.....the shielding is melted

I had 1 like that also, replaced the diode and ground wire and it works fine now.

 

[minitrucker]

id like to try and fix it myself im new too cb's

 

[SkipJunky]

It's not that hard, if you have a soldering iron go for it.

 

[park]

id like to try and fix it myself im new too cb's

Now that's what the hobby is all about, messing with this stuff ourselves :!:

 

[minitrucker]

ok i opened it up and the diode is fried so im gonna go get a new one tomorrow.......and a small piece to fix the fried ground......can u guys give me tips to find were to unsolder them from the bottom of the board thanks for the help! jesse so

tomorrow im gonna buy a small pair of cutters and pliers to get in there..........also can anyone tell me which little things to turn too tuned it.......im gonna try and do it myself and turn this radio into a "project" radio too learn on

 

[mopar2ya]

Please make sure you follow my instructions before you buy parts and start soldering.

As far as tuning up the radio....

Take it one step at a time my friend. Get it fixed, then worry about the rest.

Good luck,

Mopar

 

[minitrucker]

k i cut the diode and it works fine now

 

[Moleculo]

Kewl, now sell it to me hehe.

Is this radio stock?

 

[KC2OST]

k i cut the diode and it works fine now

You need to replace the diode and the burned wire.

 

[minitrucker]

how do i find which ones to unsolder from the bottom?

 

[minitrucker]

i might sound dumb but how do i unsolder it ?