Mz-e710 Player Won't Play - Help?

[tigertowner]

Hi folks. First time poster here, maybe someone can give me some ideas about my problem.

Just got ahold of a used MZ-E710 that looks like new in box, but doesn't want to play any discs properly. I've tried several discs recorded on different machines in SP, LP2, and LP4 modes, all with similar results. Here's what happens:

When disc is inserted in the E710, it spins up (disc icon on display rotates), but there is no sound, until about 20 seconds passes. Then it plays for a few seconds and the sound stops. After a period of 20 seconds or so, it will play again for a few seconds from the point where it left off. The time counter seems to accurately display where it is on the disc. When it plays, there are dropouts, and peculiar screeching sounds occasionally. In LP2 mode it will play for a little longer each time than on a SP recording, and with an LP4 recording, it will play almost continuously with dropouts, distortion, and noises, but will eventually hang up again.

It appears to be reading the TOC properly, as it will display track names accurately and advance tracks on command - though when it gets to a new track, it still pauses for a good while before it plays anything. I have tested it with a fully charged battery, and with the external AA battery attached.

I wonder if this is some kind of head offset or alignment error. And if so, can it be fixed in firmware by going into the service mode. And if so, how would I go about it. I've never tried anything like that before. The closest model service manual I've been able to find on line is for an E909. Would that use the same procedures and codes in the service mode?

One worry I have is related to the fact that this appears to be a unit sold in Japan, as most of the literature is in Japanese (though there is an English owner's manual), and the AC power adapter in the box is rated for 100 volts input. If the previous owner connected this to 115 volts, would it damage the hardware?

If anyone has run across a problem like this before, I would greatly appreciate any advice you could give. Thanks.