Audio Systems: Hello, laser diode, optical pickup

Question
I have a Jensen radio. Serial # is OPO112079694. When I put a CD in it comes up with an ER-04. I have tried every CD that I own. What is wrong?

Answer
Try a reset.  This may clear the problem.  Let me give it a 25% probability.

If the reset does not help then you will need to service the unit or replace it.  The error message comes up when the laser diode or optical pickup system is not recognizing the presence of a disc.  It can be from a bad laser diode or a badly aligned optical head (from dropping the unit or bumping it severely). Unfortunately, service for these conditions is usually more than the price of a new radio.

If  you could give me the model number I can give you a more precise answer; but it may not change from the above.  It may be I can give you a more detailed explanation of the cause, but the cure will remain as above, I am sure.  

If the unit is older than a couple of years I would say just replace it.

If new, maybe it is still under warranty?  

Best wishes,
C