I have a Sony Hifi VCR from about 1998. It's a 4 head machine and the model number is SLV-X825. It no longer plays or records in stereo. It still receives broadcasts in stereo, and the sound is excellent, (in fact better than my brand new digital set top box) and the picture remains crystal clear, but tapes are all in mono now. If I put a factory made movie in it, the stereo light flicks on for a split second and then dissapears. It's not a fault with the stereo light, as the equalizer on my amp indicates both channels working on identical levels all the time when a tape is playing.
Does anybody know what this might be? If so is it an expensive repair? I'd like to keep it going as it's an otherwise excellent machine and I have heaps of tapes.