Hello everybody,
I'm trying to fix an old Sony vcr with some PS issues and unfortunately from the service manual (the one with electric schema) I've downloaded from this very good service the PS circuit is missing. 

Anyone with the original manual may help me?

Thank you!
Franco

I'm encountering an issue with my Super Betamax player. During playback, some cassettes abruptly stop playing at seemingly random points, accompanied by a sound similar to the one made when a tape reaches its end. This interruption also renders the rewind and forward buttons unresponsive. However, it does not impede the manual forwarding or rewinding of the cassette. The only solution seems to be ejecting the cassette and reinserting it. Occasionally, even this workaround fails, allowing only two seconds of playback before the problem recurs.

I sought guidance from the Mister Betamax troubleshooting page, which indicated that the tape safety device might be the root cause. I received additional advice suggesting that the issue could stem from one of the sensors within the VCR, possibly due to oxidized contacts causing intermittent operation. It was recommended to resolve this by carefully cleaning the contacts on the sensor switch responsible for detecting loaded tapes or the sensor that detects if the tape is "record-protected." Another suggestion was to monitor the output of these switches using an oscilloscope or voltmeter to determine if they are indeed the source of the problem.

I'm eager to hear if anyone has additional advice or personal experiences to share regarding this issue.

Additionally, I'm facing an AV cable problem where the yellow AV cable fails to display any video. While it used to work correctly, the AV audio cable still functions properly. As a temporary workaround, I've been using a coaxial cable and routing it through another VCR to utilize its AV output. However, I'm interested in exploring potential solutions to fix the issue with the yellow AV cable, if possible. Any insights or suggestions would be greatly appreciated.