Sony SLV-315 VCR Repair - complete bottom-side tape loading gear mechanism - fixes blue screen problem
This Sony SLV-315 VHS VCR is probably from 1992. This article is a second part of the previous repair project to fix its power supply. Once its power supply is fixed, the VCR can load tape, but displays a blue screen with no video or time tracking. This was my first VCR repair and I had no past experience with such project.
I realized that one of the two split tape loading arms was not moving after the cassette is inserted to load the tape to wrap around the video head drum. In addition, the half load arm also seemed to be stuck, which is important in properly keeping the tape in place as it plays.
With the bottom cover removed, I found a plastic gear broken into two pieces. Initially I thought it would be practically impossible to find a replacement as this is an old VCR in a digital video age. It is also a highly specific part. To my surprise, I found a company that carries it. To continue my experiment I bought it.
Without a repair manual and previous experience, it was a reverse engineering project for someone like me who is more of an electronics hobbyist than a mechanics one. Nevertheless, with some trial and error, I found that it is very important to align all the gears and cams according to the little dots, holes and arrows etched on the plastic parts, starting from the left side toward the right side (split tape loading arms side). It is much easier to see this in the video. For future reference, I also included a high resolution photo below. Pay attention to every single detail as if one alignment is off, the entire alignment of the mechanism will be off and you may even damage another plastic gear.
The half load arm became stuck when pushed into another position, when it should normally spring back quickly. This was an easy repair because all you need to do is to dissemble it with a pair of pliers, clean and lubricate it and put it back. I believe the original lubricant was a type of grease, which is why with time it became sticky. Something like Lubriplate brand grease is good for this application. If you cannot easily find it, using a paper or cotton swab to rub some WD-40 on the metal rod itself will also do the job. You may need to lubricate it more often, but it is certainly better than keeping it stuck.
After replacing the broken gear and meticulously realigning all the gears and cams, clean and lubricate the half-load arm, the VCR’s tape loading mechanism now functions correctly again.
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