TK-762H programming problem

westcoaster · Post by **westcoaster** » Thu Nov 10, 2005 11:27 pm

I have a Kenwood TK-762H two channel radio that I can't get into to program. I have the proper software and cable (tested and verified operational with a TK-760H)
Whenever I try to read the radio I get the following error

ERROR!!
Check connection. Retry or Cancel ?
Take radio out of scan
Take radio out of transmit

I am able to clone the 760 to the 762 (this is permitted as per service manual) however this doesn't allow me to do a tune up on the radio.

Any suggestions on how/where the problem could be?
I have checked for cold solder joints and bent pins

Thanks in advance.

n5tbu · Post by **n5tbu** » Mon Nov 14, 2005 6:34 am

Check for 13.8 volts on pin one of the mic jack,there was a problem with a trace opening up that was common.
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westcoaster · Post by **westcoaster** » Mon Nov 14, 2005 10:08 pm

n5tbu wrote:Check for 13.8 volts on pin one of the mic jack,there was a problem with a trace opening up that was common.
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with the radio powered on and no mic the voltage was floating somewhere between 7 and 8 volts. this was between pin 1 and the chassis of the radio.

What is the "industry standard" fix for this? I am not seeing any physical damage to the trace.
I could run a jumper to pins 13&14 of the ribbon cable.... It would look like crap and be fragile.

Thanks for your input,
Jarl

westcoaster · Post by **westcoaster** » Tue Nov 15, 2005 12:16 am

Well, it's not a trace problem. I went to work with my multimeter and traced the problem back out of the head and onto the main board. R247 (4.7 ohms) is open. when I put my multimeter across this component it still reads ~
i'll try and replace this tomorrow and post back....

n5tbu · Post by **n5tbu** » Tue Nov 15, 2005 7:11 pm

I seem to remember that resistor was about an inch away from the mic jack....but maybe not.
Look carefully at pin one and make sure it has not slipped into the pin 2 slot,this usually burns the trace or that resistor,I had a 730 hg over the bench yesterday with that problem.
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westcoaster · Post by **westcoaster** » Tue Nov 15, 2005 9:01 pm

Problem solved!!!
R247 (4.7 ohms) was faulty (open) preventing the 13 volts from getting to pin 1. I am now able to get into the radio and program with the software. It is unlikely the resistor will go again (used a 1/2 watt as that is all the store had) I checked to see if there was any reason for the component failing, tested to ground etc. and could find nothing wrong. So long as it holds up long enough for me to take it in and get an alignment done, I'll be happy.
Thanks for the help!
Jarl

n5tbu · Post by **n5tbu** » Tue Nov 15, 2005 9:05 pm

Glad we could help..your problem was likly caused by a frayed mic cord,that shorted that resistor till it burned open.
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