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Cobra 2000gtl clock resets every time i turn it ON?

J

jtrouter

Well-Known Member
Jul 7, 2015
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Hello,
So i have fixed all the problems that i did have with my 2000, other than a non critical one.
When i turn on as is press the power button my clock resets back to 12:00. So i am asking
if anyone has had this happen or know what i should look for? I did find 1 posting on here
about the same problem but the possible repair was not detailed enough for me to figure
out what i needed to replace. There was a Zener diode involved that i could find but the rest
was a mystery. So if anyone can help point me to what i need to replace i would appreciate it.
Thank you all.
 

nomadradio said:
This is a symptom I associate with failed electrolytic caps in the clock/counter module. Never have established just what the mechanism of the fault is, but replacing all 10 or 11 electrolytics in the module usually fixes it.

73
Click to expand...
My 2000 is doing the exact same thing. Turn on radio and the clock resets. Can someone confirm that the caps in the freq counter are the problem and need replacing?
 
I'll confirm that I said this USUALLY fixes it.

Can't remember the last time it didn't fix this issue. Doesn't guarantee this is the only fault, but "usually" means every time that I can remember.

There is no good way to find out other than the replacement routine. Seems to me I posted pics of the "combover", using the extra wire lead sticking out of the pc board's solder side to make sure a foil trace on the "top" or component side didn't get damaged by removing the old part. The clock/counter is built with a circuit-board technology called "double sided plate through". This means that there are circuit foils on both surfaces of the laminated board. Each hole in the board has a metal sleeve inside it that completes a circuit from top side foil to bottom side foil. On some connections, not all. Any time there is a doubt about one of these sleeves coming loose, the lost connection can be "jumped" by laying the capacitor lead's excess length down and lap-soldering its long end to the foil pad that will complete the circuit.

Somebody (else) needs to come up with a step-by-step video showing how not to damage this pc board when re capping it.

73
 
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nomadradio said:
I'll confirm that I said this USUALLY fixes it.

Can't remember the last time it didn't fix this issue. Doesn't guarantee this is the only fault, but "usually" means every time that I can remember.

There is no good way to find out other than the replacement routine. Seems to me I posted pics of the "combover", using the extra wire lead sticking out of the pc board's solder side to make sure a foil trace on the "top" or component side didn't get damaged by removing the old part. The clock/counter is built with a circuit-board technology called "double sided plate through". This means that there are circuit foils on both surfaces of the laminated board. Each hole in the board has a metal sleeve inside it that completes a circuit from top side foil to bottom side foil. On some connections, not all. Any time there is a doubt about one of these sleeves coming loose, the lost connection can be "jumped" by laying the capacitor lead's excess length down and lap-soldering its long end to the foil pad that will complete the circuit.

Somebody (else) needs to come up with a step-by-step video showing how not to damage this pc board when re capping it.

73
Click to expand...
I will add something here regarding the damage to the board by removing the caps. What I have learned is that there is not enough heat transfer and space in the through-hole pads that the cap is soldered to when the cap is in it. This inhibits removing or sucking out the solder first. The only thing that I have experienced that has made this easier is to add some solder to each pad 1st then heat the pad and pull the cap out. You will need to heat one pad lean the cap and then heat the other pad and lean the cap back. This may take a few attempts back and forth to get each cap out. once the cap is out then you can use wick or your solder sucking device to clear the hole of solder. One thing to note with this. Do not leave the heat on the pad very long. Repeated heat on the pad can weaken its attachment to the board and then the pad/trace damage occurs. Best of luck. It's hard but not impossible.
 
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nomadradio said:
I'll confirm that I said this USUALLY fixes it.

Can't remember the last time it didn't fix this issue. Doesn't guarantee this is the only fault, but "usually" means every time that I can remember.

There is no good way to find out other than the replacement routine. Seems to me I posted pics of the "combover", using the extra wire lead sticking out of the pc board's solder side to make sure a foil trace on the "top" or component side didn't get damaged by removing the old part. The clock/counter is built with a circuit-board technology called "double sided plate through". This means that there are circuit foils on both surfaces of the laminated board. Each hole in the board has a metal sleeve inside it that completes a circuit from top side foil to bottom side foil. On some connections, not all. Any time there is a doubt about one of these sleeves coming loose, the lost connection can be "jumped" by laying the capacitor lead's excess length down and lap-soldering its long end to the foil pad that will complete the circuit.

Somebody (else) needs to come up with a step-by-step video showing how not to damage this pc board when re capping it.

73
Click to expand...
I did this last year to my 2000. Rather than using a cheap vacuum sucker or wick i went on Amazon and bought a 30 watt desoldering electric vacuum solder sucker for
around 35 dollars or so and i did all the caps in the radio and It was so EASY with that tool. I have always used the two others that i mentioned and alwasy hated removing pars, But now i use all the time and love it.

​

 
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jtrouter said:
I did this last year to my 2000. Rather than using a cheap vacuum sucker or wick i went on Amazon and bought a 30 watt desoldering electric vacuum solder sucker for
around 35 dollars or so and i did all the caps in the radio and It was so EASY with that tool. I have always used the two others that i mentioned and alwasy hated removing pars, But now i use all the time and love it.

​

Click to expand...
jtrouter, please send me the link to this machine. thank you.
 
HavaV10 said:
jtrouter, please send me the link to this machine. thank you.
Click to expand...
I see NZ8N has already posted a unit the same or even better than mine, And the one i bought is out of stock the one he linked will do you nicely. Enjoy using it you will no longer worry about replacing parts.
 
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I have the cheap SS-02 with the silicone tip from mouser. I wiped out the factory grease and replaced it with silicone dielectric grease and the suction was much better. Great little tool for its price once you get some practice with it.
 
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