Hi different expert here.
Is the problem ONLY that the unit will remain on while the button is pressed and ONLY shuts off if you release it?
Hi thanks for your patience!
This is one that simply needs a professional tune up.
It is doing exactly what it would if that were the case and the unit hasn't been abused. Sears can do this for you or just about any local home audio shop local to you can make this fix, as well as Best Buy. Best Buy and Sears both will send it out for the fix;-) But they are very good and both are fair priced.
I would have this one repaired its a good unit and the cost should be prohibitive;-)
I hope this helps.
Have a great Sunday and if you have any further questions please ask me.
Don't forget to rate, once you do, you still will have access to me until this is fixed.