The Volvo installed 6 CD changer on my '95 850 wagon has stopped working. Initially the currently playing disk stopped and I got a flashing 'H' error message on the LCD head unit display. At that point other disks in the changer still worked. Then I got the 'H' message for all disks. I checked fuses and connectors and all are in place. The disks feed from the cartridge in and out of the disk reader area, but apparently the reader doesn't read the disks. Earlier today I switched to the function on the head unit from CD to tape and back at which time the CD played briefly, but with the choppy sound that usuallly means the disk is unreadable. This doesn't seem related to a particular disk bvecause I've tried a bunch of disks. Now all I get is a flashing disk number followed by the 'H'. The head unit is an SC 811. Any thoughts? I'm hoping I don't need to buy a cd changer, but...