Panasonic SC-AK78 The stereo lights dont come on , no sound . I i I have to turn the power on & off numerous times for it to work , the lights sometimes stay frozen ,meening if i change from stereo to CD itwill stay on stereo but i can ply CD`s . For the most part there is no sound in come`s & goes at will.

This is a sign of a power supply problem. These units use what is called a "switch mode" power supply. These use a capacitor to kick-start the power supply. While I can't say for sure, this is the most likely cause. There are other components that can be close to failure later in the circuit that can cause this as well. Without seeing the actual unit and testing the circuits, there is really no way for me to know. You should expect to pay in the $20 range for parts for this repair.

Dan