After pouring over the wealth of information available in Janice's Novel thread and other posts from the archive, I decided to tackle the problem my back-up Sankyo was experiencing: Switched to forward it would run for about 20 seconds then the motor would quit like someone had pushed pause. then after a few minutes it would begin to run again for another 20 seconds and so on. In Janice's thread it looked pretty simple to remove the speed control board so without expensive meters on hand I decided to pull the board from my main working projector and swap it into the second machine. Sure enough, the machine ran perfectly with the replacement board. Knowing this, I ordered components that were replaced in The Novel thread, with three additional capacitors that looked bad to me ( Brown leak stains ). When all the pieces arrived I started by replacing the Largest capacitor, the Transistor and the Bridge rectifier. I popped the board back in and still stalling after 20 seconds. I then replaced the three suspect capacitors and tried again. PRESTO!
The second machine now runs non-stop until I switch it off!
The arrow shows where the transistor was replaced, the top circle is the large cap and rectifier, smaller and to the left are 2 caps that were replaced but I believe, without a meter to confirm, the smaller single cap on the right to be the culprit. Schematic has it tied into the rectifier, large cap and transistor circuit. I was in pretty bad shape when I removed it...Nice to finally have 2 fully functional Sankyo Stereo 800's. A real performer!
The second machine now runs non-stop until I switch it off!
The arrow shows where the transistor was replaced, the top circle is the large cap and rectifier, smaller and to the left are 2 caps that were replaced but I believe, without a meter to confirm, the smaller single cap on the right to be the culprit. Schematic has it tied into the rectifier, large cap and transistor circuit. I was in pretty bad shape when I removed it...Nice to finally have 2 fully functional Sankyo Stereo 800's. A real performer!
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