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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc.

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Old 23rd Jul 2020, 3:40 am   #1
TheWire
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Default Sony Betamax C7 no video

Hi,

I'm trying to get an old Sony betamax SL-C7UB to work again after being in storage for 30 year or something.

I managed to get tapes to eject, rewind, fast-forward and play after some initial problems with the mechanism sticking. I just can't get any video output.

The test video and audio signal works fine and audio from tapes works but only via the phono out not the aerial output. I have tried using a composite video cable but this doesn't work either.

I get no video of any kind no static or anything on both aerial and composite output.

Anyone have any idea what might be wrong?
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Old 23rd Jul 2020, 11:22 pm   #2
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Default Re: Sony Betamax C7 no video

Do you get any signal passthrough (E-E mode) from the tuner or if you plug something into the video input of the C7?
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Old 24th Jul 2020, 5:53 pm   #3
TheWire
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Default Re: Sony Betamax C7 no video

E-E works, so does video input.

I think the problem is being masked by the fact that modern TVs instead of showing static when un-tuned or when there is no signal only show a black screen.

I noticed I could see a brief glimpse of something between switching the test signal from on to off when playing a tape. It seems the video output is so bad the tv considers it not an actual signal so shows only a blank screen. I tried using a different TV and I was able to get a picture briefly

So it seems the actual problem isn't that there is no video output but just the video output is extremely bad.
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Old 25th Jul 2020, 12:33 pm   #4
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Default Re: Sony Betamax C7 no video

Possibly a silly quation, but are the heads clean? Might be worth seeing if there's anything in pause or picture search when less muting is applied.
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Old 25th Jul 2020, 5:16 pm   #5
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Default Re: Sony Betamax C7 no video

Always use an analog TV/monitor when testing this kind of equipment. Most modern sets treat unstable signals as unusable and therefore they just display a black/blue screen instead. As Glyn pointed out, make sure the entire tape path is clean. Cleaning the heads on a machine that sat unused for 30 years is mandatory. The C5/6/7 machines are known for their failing capacitors in the servo circuit. That would cause the head drum and/or capstan speed to unlock and in that case there would be no stable video signal coming out from the machine.

Regards,

Fivos
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Old 25th Jul 2020, 6:02 pm   #6
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Default Re: Sony Betamax C7 no video

When cleaning the heads make sure that that you also clean the audio control head assembly.
If you have no control pulse it mutes the video on these vcrs.

Dave
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Old 27th Jul 2020, 12:03 am   #7
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Default Re: Sony Betamax C7 no video

Check too the RF Envelope first.

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Old 27th Jul 2020, 10:31 am   #8
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Default Re: Sony Betamax C7 no video

True - that's why it's best to use an old TV and try picture search to see if there's any picture visible.
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