Uniden PC-122 Loss of receive audio

[TonyV225]

I have 2 of these radios one works amazingly but the channel led display is pretty much burnt out and I dont know if a replacement is available but other than that the radio is super. Now the other has the same problem with channel led display being burnt out but the major problem is it transmits and it receives well atleats shows that it is on the radios meter but there is no sound in the radios speaker nor will it give sound through an external one. I had replaced the audio chip and that wasnt it also the PA works aswell this has me baffled an I can really use some help hereb anyone ever seen this or heard of this?? Any help would be totally and completely appreciated I am and the end of my rope with this SOB :roll: I have bben messing around with this damn thing here and there for about 2 years now

 

[lords]

solder joints between front panel and mainboard may be cracked
and for the channel display its a standard one you can get off ebay or cb sHop

the 810 and 500 should be the same stuff...you got to check it
audio-info

 

[Switch Kit]

Back in Febuary I suggested that you change the two large caps in the radio which I felt would fix your problem . Did you try that ?

 

[TonyV225]

Yupp Jim I did that as a matter of fact I have plenty of Extra caps to boot LOL. It just royally sucks because radio transmits excellent and sounds fabulous to boot I just want it fixed and without having to spend money shipping it out. I know its something simple and stupid. If I have to send it out then so be it so Jim if I cant figure it out you want to take a crack at it if I send her out to ya??

 

[Switch Kit]

Back in the day Tony , I personally couldn't figure it out myself , I sat there with the tech at the time as he went through that radio for about an hour , those were the last two parts he had changed at the time and the audio came back to life , I don't think he was even sure what caused it ? It cost be 40.00 for his time , but like I said , I sat there for an hour as he went through the radio , so he pretty much earned his money , even though even he didn't seem that sure about it and why ? Did you also try to change the big cap right next to the audio transformer ? other then that , I've been there and done that and it ended up costing me more then I felt the need to pay for it , at least in my case , there was no shipping costs involved. You can pick those modeled radios up on Ebay for not much more then what I paid to have mine repaired at the time. It was just something I had to know , but in the end , it had even been guess work by the tech to a degree ? but he fixed it all the same. Those are good decent little radios that will show very good numbers , over the years I have leanred that it is very wise to not push those numbers with those radios , they tend to run very hot for natural reasons to begin with , running them with lower numbers concerning AM/SSB and letting an amp take care of business would do wonders for the longevity of the radio. You can usually fry an egg on the Voltage regulator / audio chip on those radios You can also help heat on those radios by putting the heat sink that's over the finals inside the radio on the outside of the radio. Hang in there Tony , if there's a will , there's more then likely a way.

 

[TonyV225]

Hey jim i just noticed that the 2 caps i changed were the 2 bigger ones the farthest one back in the corner the next one foward near that one (you have it circled) but I didnt change the smaller one you have circled towards the frontend or middle shall i say its the smaller one of the 2 you have circled that I have to try replacing.

 

[bushwacker]

Make sure you got tx audio..... the problem with those radios is they inherently run hot..... especially the audio IC. Make sure thats good.
Sounds like you did that already. I've had a problem with tx/rx switching in one....
Just make sure your seeing rx on the signal meter so you know its rxing. Get a speaker with 2 wires attached.... put one wire to ground and the other touch to the output of the audio IC and see if you can get any rx audio out of it. If its a problem around the audio IC you just need to figure out if the problem is before the audio IC or after the audio IC.... checking the output of the audio IC right at its output will give you a good idea if your getting anything out of it to the speaker line. If you do, then you just have to trace the audio with the speaker to where the audio stops.
If you don't get anything out of the audio IC you will have to trace the input.
Grab a schematic and trace the rx audio through... double check that its actually going into rx mode.

Great radios... I got one of those thats modded alot... that radio is still one of my favorites.
Good luck... hopefully Switch's ideas help you out... if not you can always trace it through.
Take care