Radio worked fine......then I was trying to find another channel by turning the tuner knob and all of a sudden it just locked and when I turn the tuner knob it won't change stations. Nothing works but the on off knob. What happened???

Turn the main (volume) knob all the way until volume reads 00, leave the button (volume) pressed until the radio beeps - be patient it takes a while - after this turn the knob all the way or until you reach an acceptable volume limit, push the knob again until beep then turn radio off.

First unplug it. Sounds like you need to spray some tuner cleaner in the pots that are crackling. Pull the knob off and you should be able to use a spray can of tuner cleaner with the straw that comes with them to spray into the potentiometer , then rotate the pot several times while it is still wet. After cleaning them all, wait 10 minutes and then try.

TAKE THE KNOB FO AND SEE IF IT WILL TURN BUY HAND IF SO JUST PUT A BIT OF PAPER ROUND IT AND PUSH THE KNOB BACK ON AND IT SHUOD GO

If your scanner is open squelched on one channel, try blocking that channel out. Some times a channel can get jammed if someone has a mic cue button stuck or something similar.
Try locking out that particular channel and see if you get your squelch control back.

You mean a digital tuner or an analog tuner (the old ones with the cursor)?

Post for reply.
Stelios.

1. ensure that you are on the TV tuner when you are trying to scan channels
2. if analog tuner works, but you cannot access digital tuner....the digital tuner is broken

When you turned channels before, did it switch between analog and digital channels seamlessly or did you need to press a button to acces digital channels seperately?

If you accesed digital channels seamlessly, #2 is not likely
If seperately, #2 is very likely.

replace Bad Circuit Dsp Pcb the rca part number is #265973

This worked for me (radio in 2003 VW Golf):
Radio says "CHECK" but is otherwise unresponsive. Turning car or radio on/off doesn't help.
On the far right of the radio, there's a round TUNER button. Press it for 5 seconds. Your screen will then show some digits, but the unit is still unresponsive.
Press tuner button again for 5 seconds. Radio should now be 100% again. Let me know if this works for you.

Moving the volume/on/off knob to make the radio work again is interesting and a good clue. On most CB's, the pot is probably soldered directly to the printed ciruit board.

It's possible that there is a bad solder joint to the power connections on the pot that turn the radio on & off. If the solder joint is bad, it can still make a connection but the connection will have added resistance in line. The on/off switch can be bad too.
Switches arc each time they are used and over time, the contacts become pitted and make poor connection.

I had a stereo receiver where the tuner lights flickered and there was electrical noise in the receiver. It turned out to be a bad on/off switch.

This resistance may be low enough not to affect the radio when in the receive mode but when you transmit and draw more current that resistance will be noticable during transmit.

The fact that you rotate or move the volume/on/off knob and the radio starts working again, tells me that there may be a bad connection in the radio.

A cheap thing you can try is spraying some electrical contact cleaner into the pot and rotate the pot back & forth several times and turn the switch on & off several times to clean it.

Please let me know if I can be of further assistance to you.

Good luck!

- Jim