Quote:
Originally Posted by waltchan
Glad I don't have any early Mitsubishi VCRs. I just cannot recommend early Mitsubishi VCRs for the super long run.
Replacing the upper cylinder requires a little star screwdriver to remove the shaft in the video head drum. Sometimes, soldering is required to remove a circuit board on top of the upper cylinder. Not sure about Mitsubishi, but early Panasonic VCRs made before 1982 have the easiest video head to change, in my opinion.
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Problem I almost always ran into on the Panasonic-made machines was the new upper cylinder, even the OE Matshushita replacements, not fitting snugly to the hub, making the upper cylinder a bit eccentric unless you got real lucky. This would result in a lot of flutter in the linear audio on playback. I resolved that by making a test tape at SLP with color bars and a 3kHz tone recorded on it, on a machine that exhibited very low wow and flutter. I would then play that tape back with a wow/flutter meter plugged into the VCR audio output, and with the uper cylinder screws barely snug, with a plastic screwdriver handle very lightly tap the upper edge of the cylinder as it was running. Yes it sounds crude, but it works! After a few taps the upper cylinder would land at a position where the flutter would drop to less than .1% which is very good, and tighten the screws down at that point. This same tape with the 3kHz tone and W/F meter was a good diagnostic for a bad take-up clutch that plagued those Pannys in those days. The clutch would get sticky and worn, and make very rough almost vibrating takeup torque, which made higher than usual flutter so bad sometimes the linear audio would sound garbled. With the test tape and the W/F meter I could catch those clutches as they were beginning to get sticky and fail even if the unit wasn't in for that particular problem, go ahead and replace while on the bench: "Preventive maintenance".