I have some problems with a friend's Luxor VR3721LX (same mech. as the
Sanyo VHR4100)
I have no service info for it.
He uses it as a tuner for his TV, the problem is that the picture
doesn't sync (the scart is used)
There also seems to be a loose belt from the loading motor (nearly
hidden under a plastic cover), but the tape part is not of much importance.
At first I thought the problems were caused by bad electrolytics in the
power supply, but it seems the voltages are fine (one +65V has 10 vpp
ripple, but it doesn't get better with another cap in parallel)
Any good tips are welcome.

Stein
Trondheim, Norway

if you say he uses it as a tuner for the tv, is that because the Tv is
faulty? or simply for remote control use.
if the pic does not sync, that could also be the TV.
have you tried the video with a different tv to double-check?
-Ben