Tuning knob turns but does not move tuner bar nor change station. all else works fine.

its warned out

Since most radio's have digital displays these days, to have a pointer move along a dial implies it's either old or a retro model. In any case all that will have happened is that the chord or something in the drive that moves the pointer will have either snapped off or broken. It shouldn't be too hard to repair, though it can be a bit tricky to set it up right.

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

It certainly sounds like the main tuner has failed, if IC301 does that function I would replace it and see what happens.

This may help: If you take off the front of the radio (don't forget 2 screws in back!) you will notice a set of black and red wires running from the 2 AA backup batteries to the digital display circuit board. The wires plug into the board with a little white plug. If you unplug this the display will fade to nothing. If you plug it back in it will display an unset digital clock format. This seems to reset the radio, after which it should work.

Ok to set Manually Turn on radio Select Tuner select band. Press tuning mode button. The window should switch from preset to manual then tune up or down using the tuning preset time buttons left side/ top / Next to volume knob

FM 99.7 works best.... However if you have a local FM station using that freq your out of luck UNLESS your handy with a Jewelers screwdriver. Calling tech support will get you a "sorry" but there is nothing we can do. So if you are one of the unlucky ones with a Local 99.7 FM station here is what you can do.

1) Find a dead spot on the FM radio band either at the very low end or high end of the range. You should hear just fuzz (white noise) on your radio. However, on many newer FM tuners if there is no station broadcast there is nothing but silence.
2) Put batteries in the microphone.
3) Get a really really tiny flat head (Jewelers)screwdriver just like the kind in those eye glass kits they sell at the grocery store.
4) Sit right in front of the radio
5) Insert the screwdriver into the tiny hole in the microphone and tune the microphone until the radio goes quiet (no fuzz sound). Or.... you can keep pressing S to hear a beat and the beat is acutally heard through the speakers.

The hole is located just to the left of the screw that you undid to get at the battery compartment, but it's off center. Inside this hole is a small tuning screw. Slowly, slowly, SLOWLY turn the screw driver until you here a change or interruption in the fuzz sound on the radio speakers. This will indicate you found a compatible frequency. Then even slower - tune back to that "notch" until you hear nothing but silence on the radio. Test it by pressing the applause button "A" or by pressing the mic "M" button and talking.

There are multiple places on the FM dial that will "work" as you tune the little screw but you should have already manually selected where (the FM freq) you want to use your mic.

Once it's working it ain't perfect. I doubt you'd do a serious performance on it, but the kids love it.
The mic quality is not top notch for sure.

Fine tune as necessary....

Kelly

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

This sounds major.....

The signal detection used in both radios and TV sets is via special voltage sensitive diodes which alter capacity as the voltage across the diode changes.
You actually change the voltage across the diodes as you move the tuning dial.

In your case the diode only sees one voltage and is locked to a certain station, because you are not altering the capacity to re-tune to another station...

So it appears that you have lost the ability to alter the DC voltage across the diode...

The design of the tuning knob may be where this fault lies, where the physical action of turning the tuning knob does not transfer the mechanical action to the item that changes the DC voltage to the diode....maybe you have systen that uses a long cord would around pulleys that gives you nice control over the tuning maybe its just a broken tuning cord...
Maybe the tuning is done by just a simple variable resistor I'm not familiar with this system but I have given you the bascics to start on...Unplug the cord from the AC wall socket then remove the top of the cabinet and have a look to see what moves when you turn the tuning knob it will soon become apparent if there is nothing moving when you turn the knob and thus lead you on to the problem....
Maybe the knob is just loose on its drive shaft...

Cheers From YUBEUT