The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Radio Make and Model: Uniden PRO 510xl
PCB Number: PA-402AA 1/3 (i think)
PLL Number: SM5124A
Test gear available: VOM
Symptoms: audio IC gets hot

The radio works fine. I just bought it on ebay. I noticed that while the unit is powered on, the audio IC begins getting warmer and warmer until it is hot to the touch. This was tested without transmitting and volume/on - off pot was set at low volume. Also I am not using external speakers.

Any help would be most appreciated.

Hi.
I'm not working from a schematic here, but you might want to check to see if there's a large value capacitor between the audio chip and the speaker. If fact, just lift the audio lead to the speaker or insert a remote speaker plug into the jack... with nothing connected to it. Anything to remove any DC load from the chip. If there is a capacitor between the chip and the speaker, and if it is shorted, it will cause the chip to get too hot.

Good hunting!

Stan