Many folks including myself either are replacing or have replaced the Quest unit. If you do a search on the quest topic you will find alot of info on what folks have done. This is one area Keystone is really lacking in quality when it comes to the options of dvd/surround sound systems they could have used.
Here also is a name and phone number from another post about this very same Quest problem you are having.
Keystone did the following to another member:
"They transfered me to a John Mochamen of The Odyssey Group. He has been most helpful. You can reach him at 574-848-2294 or
johnm@odygroup.net"