Sony SL-HF 950 power problem? (PAL Betamax)
 

Hello,

i got a used SL-HF950 Betamax machine. Unfortunately it will not power up completely.

When i plug it in, the clock is showing up. By pressing the power button, the display is coming up fully.
The Power LED is getting on very shortly, but then switch off immediate again.
The LEDs for forward, backward etc. are on, but if i press the related buttons there are no any drive functions.
Also the tray of the cassette loading doesnt work. There is still a tape inside.

I replaced the Power Supply with a known good one from a working unit, butt still the same issue.

Any help would be highly appreciated.

VCRs are usually designed to self protect if the internal sensors detect what the controller believes to be a mechanism jam. This could be caused by a real jam, or a weak/failed component in the VCR mechanism, or the mechanism having slipped a cog or two and lost its timing.

If you want to try DIY repair, I would seek out the service manual for the VCR. It usually will have instructions on how to remove a jammed tape if the controls cannot eject it normally. Then you can start from scratch and troubleshoot the machine. A WEB search may turn up suggestions if this is a common issue with the VCR make/model.

I don't know if its part of the main power supply, but the "STK" power IC/regulator tends to cause problems in late-80s Betamax decks.

https://www.palsite.com/tech.py?model=950tech.html

PALsite is a good reference for this PAL market deck, there is also a technical forum/mailing list you can search or post.

https://chat.palsite.com/chat_page.py?r=1&cp=Betamax;

Note: This deck was sold in the USA as the SL-HF750, its service manual may be helpful for diagnosing this model if you can't find one for the SL-HF950. Sony's decks were very touchy machines, and they haven't exactly aged all that well!