Uniden pc122xl no tx or rx

[TM86]

Hi
Checked voltage at ic4 and have 13.5 at one pin and 8 volts at the other also i have no way of checking frequency at the pll do i need a scope for this measurement also no popping when radio is powered up no volume with squelch down at max volume its like its not switching between pa and radio but i checked the switch and it seem to be switching when i did a continuity test at the solder connection i replaced two 1000uf 25v caps next to power supply one was faulty maybe other caps need replacing radio didnt die whilst transmitting i put radio into moth balls and the next time i turned it on nothing
Thank joe

You should probably have at least an oscilloscope, frequency counter, and DVM for radio repairs. Add a frequency generator for alignments.

In this case, though, if it was working before you put it in storage and now it's not, I'd start looking at recapping the radio. Hopefully it's just a bad electrolytic and nothing else got taken out. Site member Klondike Mike sells cap kits: https://klondikemikescapkits.com/co...65-uniden-pc-122xl-electrolytic-capacitor-kit

Also, if it has some hardened brown glue in it, you'll want to get that stuff out. It gets corrosive and conductive and can eat the legs off of components.

 

[sp5it]

Replacing all capacitors without diagnosing is not so smart move
Mike

 

[Caveman67]

Gday
I have a dvm,freq counter several radios watt meter dummy load what i dont have is an esr meter to test caps incircut without replacing all caps and no oscilloscope but im willing to get one any suggestions!
Thanks joe

 

[Caveman67]

Gday
Not much glue was used in this radio just a bit around the caps i replaced no corrosion anywhere in the radio i think maybe caps that have degraded in storage just a guess

 

[Uncle Ronnie 336]

does the tx light illuminate on transmit?

 

[Ghetto]

pc122 troubleshooting thread with no tx/rx:

Thread 'PC-122 Troubleshooting'

Feb 24, 2020

I have a Uniden PC-122 that I have had since it was new, about 1993. It is unmodified. I dug it out recently and powered it up. Channel display and everything else seems to be working perfectly, but it neither receives nor transmits in any mode. Tried an external speaker; still no band noise. The PA function does work, hence the modulator works. I opened it and looked at the board, didn't see anything amiss. None of the electrolytics are swollen or anything like that.
I've reached out to Handy Andy because I've seen references to information he had on cbtricks, but don't have access to the...

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• Replies: 27
• Forum: CB and Export Equipment and Accessories

robalo mentions in that thread:

"C101 - takes out AN612. Kills 1/2 the IF for anything AM or SSB..."

Have you contact/circuit board cleaner sprayed everything/connectors etc and just check for dry solder joints. Could also have the radio running and feel around with your finger, see if RX comes back by lightly prodding/flexing the board and its components (highly technical....) which may give away a dry solder joint problem.

 

[Caveman67]

Thanks for finding that thread ill check it out

 

[Caveman67]

Gday
Tx light doesnt illuminate! replaced c101 still nothing im still to check voltages on pll ill post back when ive carried out those measurements
Thanks joe

 

[gcook]

It's extremely difficult to fix anything without the proper tools. It takes years of experience to tackle two-way radio repairs properly, and with confidence. Asking people questions on the Internet is not the way to do it. Get some books and start reading.

 

[Caveman67]

Gday
The internet is a wealth of information and i believe somebody here can help
Eg a friend of mine is a mechanic we have a electrical problem with the car taking out the headlights we need lights to drive home 2 hours there is a short in the wiring but where is the short within 5 minutes of dr google we were on our way the short was under the car rubbing against the exhaust when its a common fault it usually affects all cars in that line
Also a have a few book lou franklins understanding and repairing cb radio
Amateur radio handbook
Because i have limited test equipment i am here with my fellow radio operators after a hint
Thanks joe