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Old 9th May 2022, 11:31 pm   #41
19Seventy7
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

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Blimey that was quick! I'm glad it was an easy fix for you and nothing vexing. I really appreciate you doing this for me. It almost seems too simple now!
Hi '77,
Yes, that was a fairly simple one to diagnose, but still needed a 'scope and a pattern generator to get there quickly!

Sometimes a fault is easy to diagnose but the cure is long winded such as changing a multi pin chip or rebuilding a power supply. Other times the diagnosis takes forever, but the cure is a 5p diode or resistor.

Anyway, a search through a pile of old boards turned up a suitable 470 Ohm preset of the correct size to fit into the modulator. We now have video & audio coming through the machine to the RF output, so that's a good step forward.

Next, I'll turn my attention to the mechanics and find out why the tape is riding up the audio head. On the face of it, the pinch roller looks pretty good, but I can't get it off because the screw head has been chewed...

Out of interest, I powered up my 3V16 to see what the clock display was like. It too has several missing segments. It didn't have when I last used it about 5 years ago, so it would seem that it's just age that's causing the problem rather than use.

The clock rebuild process is documented here from a member of the Vrat forum (I hope its OK to post a link to that?)

https://www.radios-tv.co.uk/communit...clock-rebuild/

Cheers
Nick
That's me out instantly without a scope! Been meaning to get one but need an ISOTX first that could handle all my different things as well as.

I've been there before! I recently had frame collapse on a set of mine, turned out I'd reinstalled a diode the wrong way round, took me ages to realise!

Ah.. I forgot about the screw head, that's the original pinch roller, I couldn't get it off either. I'm not sure if I still have a replacement here. I think I might, if you need me to I can have a look and post it to you. I have a feeling it's sitting inside another (broken) VCR.. It's definitely to this model as it came with the belt kit I fitted.

Shame about your 3V16's clock too. It seems to be a more recent problem too, like you say it's probably just age. Hopefully any that get rebuilt last just as long, if not longer, with newer, improved parts.

Thanks again
'77

(Let me know about the pinch roller if you need it)
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Old 11th May 2022, 11:45 pm   #42
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

Good to hear you're getting this going. Could the pinch roller arm have got bent during a previous owners attempts to remove the screw?

I'm working on one of these at the minute. Someone's definitely been in it before me as there's hardened grease on absolutely everything. There's also flux residue on a few of the chips on the audio/servo board. The motors were running continuously. The chips with the flux on them were all ones related to driving the motors so I think whoever it was might have been trying to fix that fault but the cause of it was that one of the unload switches was bent and so wasn't being pressed in properly. IC3, the 4011 chip had flux on but was faulty and looked to be the original anyway. They've also soldered a piece of wire across the 3.15A fuse and lost the oil fence from the capstan and one of the screws that hold the cassette housing to the deck.
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Old 12th May 2022, 9:34 am   #43
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

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Good to hear you're getting this going. Could the pinch roller arm have got bent during a previous owner's attempts to remove the screw?
Yes, it was bent! I removed the whole arm assembly in order to be able to put more downward force into removing the screw with the chewed up head. With the arm supported, the screw came out quite easily. Placing the arm on a flat surface, the pinch roller end was bent down 1/16". This has now been corrected. The roller itself looks pretty good and is still cylindrical rather than barrel shaped.

It sounds like your machine has been well 'got at'. It's always a pain when so much work has been done, primarily due to poor fault diagnosis. Who knows how many other faults have been created?

Thankfully, '77's machine is in good order and doesn't look to have been messed about with.

My next task is to overhaul the deck which involves removing and carefully lubricating various parts and cleaning the tape guides etc, There is also some corrosion on the upper drum which should polish out.

Cheers
Nick
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Old 12th May 2022, 6:04 pm   #44
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

They do bend quite easily. I prefer the cast one in the 3292.

I know. Hopefully they haven't got at the presets. I wouldn't be surprised if the servo ones have been twiddled given the soldering that's gone on but I find at least the drum servo often needs setting up anyway so I don't mind that as much. It needs a lot of hardened grease removing before it will even load a tape properly. They really have gone to town with it.
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Old 13th May 2022, 12:08 am   #45
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

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Originally Posted by birksholt View Post
Good to hear you're getting this going. Could the pinch roller arm have got bent during a previous owner's attempts to remove the screw?
Yes, it was bent! I removed the whole arm assembly in order to be able to put more downward force into removing the screw with the chewed up head. With the arm supported, the screw came out quite easily. Placing the arm on a flat surface, the pinch roller end was bent down 1/16". This has now been corrected. The roller itself looks pretty good and is still cylindrical rather than barrel shaped.

It sounds like your machine has been well 'got at'. It's always a pain when so much work has been done, primarily due to poor fault diagnosis. Who knows how many other faults have been created?

Thankfully, '77's machine is in good order and doesn't look to have been messed about with.

My next task is to overhaul the deck which involves removing and carefully lubricating various parts and cleaning the tape guides etc, There is also some corrosion on the upper drum which should polish out.

Cheers
Nick
You've really gone above and beyond what was expected! Thank you so so much, I really really appreciate this I was only expecting the E-E fault to get cleared and not an overhaul! It sounds as though it's getting a good pampering with you!

I hope it's behaving for you and not causing too much havoc

Thanks again, I don't think I can thank you enough for this!
'77
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Old 13th May 2022, 12:34 am   #46
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

A pleasant evening has been spent servicing the deck mechanics. There was a lot of loose debris, bits of fluff, dust, hair and general detritus in the machine, so I gave it a gentle blow out with the air line, being careful to avoid the video head tips.

With the cassette carriage removed, good access is gained to the upper deck mechanics.

The capstan had a slightly rough texture due to tiny corrosion spots. This was removed and polished back to a shine with car body rubbing compound. A small amount of light oil was applied to the phosphor bronze bush before reassembly.

Both reel tables were removed and their spindles cleaned and suitably lubricated.

The entry & exit guides, slant poles, erase & audio/control (ACE) head were all cleaned with IPA and the mechanism generally inspected for any obvious issues. The main one being the spring on the back tension pole was attached to the wrong place. With the machine laced up, the pole did nothing by way of providing back tension which was one of the causes of the tape riding up the audio control head.

With this rectified and the pinch roller refitted with a new screw, it was time to see what we had achieved.

Both tape end sensors were covered with tape and the 'cassette in' switch held closed with more tape. This enabled the machine to be used with no cassette carriage. This allows a tape to be held in place while being played and gives good visibility to the tape path past the ACE head/ pinch roller which is where most of the issues will occur.

Rewind & fast forward worked smoothly and play produced a remarkably good picture! All the tape wandering had been cured and there was just slight rippling where it passed over the last guide before the pinch roller. Slight adjustment of the ACE head zenith (front to back tilt) cured that.

The front panel tracking control range was incorrect and produced a noisy picture on its click stop setting. This is adjusted by sliding the whole ACE head assembly on its slots. The securing screws had been disturbed in the past. Sliding the assembly back to the position that lined up with the original locking paint marks produced a noise free picture over almost the whole range of the tracking control.

I'm very pleased with the machine so far and it's looking like it's going to be a good performer. The playback picture and sound are remarkably good and the video heads seem to be pretty good too.

So far I've only seen it on a black & white portable TV as it was a mission to dig out a colour one, but that will be next I think.

Even the head drum servo seems to be perfectly happy which I have had problems with on other machines - they often seem to be a bit tetchy!

Still a bit more work to do, but it's coming along nicely!!

Cheers
Nick
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Old 30th Oct 2022, 9:30 pm   #47
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

The saga comes to a very happy end!

Last night, 1100 man very kindly dropped the VCR off after spending some time on fixing it up for me, and now it's running flawlessly, complete with clock! We spent an hour tinkering around, plugging it into various sets, both 405 and 625 lines, using both 405 line and 625 recordings that Nick made for me too all sets ran with no hitch at all, other than my unmodified G8 and pre-recorded tapes, however nicks tape, recorded on my VCR, played flawlessly.

After nick left, I sat and watched it pretty much until I went to bed, watching some Dad's Army and Only Fools and Horses, on the tape recorded by nick for me!

It's brilliant having it back as I've not been able to watch tapes for months now, or record for years due to my VCR having worn heads, so this will be well loved for sure!

Thanks again nick, I really appreciate it!

'77
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Old 31st Oct 2022, 4:12 pm   #48
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

Hi '77,

It was good to meet up with you again the other evening and finally return your video!

It has been a rewarding project returning this first generation VHS machine to full working order - especially rebuilding the clock display!

I've been using it with a '90's CRT TV and I've been very impressed by the picture quality - the designers really did push the available technology - both electronic & mechanical, to the limit in a remarkably compact machine. It's also a testament to the quality of Japanese components from the '70's. Apart from the failed LED's in the clock display, no other components needed replacing in a machine with a very large passive component count. Quite amazing for 45 year old electronics!

In early colour TV's made before VCR's were thought of, flywheel sync - a great innovation in its day for poorly received broadcast signals - can cause havoc with the output from a VCR. If the flywheel sync circuit has a long time constant, a picture with varying degrees of horizontal shaking will result as the line timebase fails to keep up with the varying phase of the line sync pulses coming off the tape.

I was therefore interested to see how well an early 520 G8 would cope with the VCR. Rather predictably, it was completely hopeless on a pre- recorded tape but was perfectly fine using a recording made on itself. A self recording drastically reduces the line sync phase errors coming from the tape, especially between each of the two video heads. The flywheel sync circuit in the TV therefore has a much easier time, resulting in a much more stable picture.

These VCR's also work very well recording 405 line material. There is no 625 line drop out compensator to get in the way on playback, which causes problems with later machines.

The Mk2 Hedghog converter can be used as a stand alone modulator and so we used this to view some 405 line material I had recorded on the 3v22. As the GEC BT302 TV had direct sync (no flywheels there!), it didn't suffer any of the problems of shaking pictures.

So all in all, a very satisfactory conclusion to the project: - it's now down to '77 to enjoy using it!

Cheers
Nick

Last edited by 1100 man; 31st Oct 2022 at 4:19 pm. Reason: typo's
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Old 31st Oct 2022, 6:22 pm   #49
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Default Re: Ferguson 3V22/Baird 8929 VCR no picture

Thank you nick, it was great to catch up with you too! I can safely assure you that my duties of enjoying it are being taken very seriously!

It's been good fun playing around with it, I'm quickly getting used to it, with things like waiting for the tape to unlace before being able to press FFW or RW!

Luckily your post made me return as I realised, I hadn't attached a picture of it, so here it is playing through the G8! As an aside with the G8, I've realised that it can play home recorded tapes made on other VCRs, although with less stability than recorded and played back on the same, but still very watchable. It's only professionally recorded tapes that it cannot handle!

Unfortunately, I didn't get a photo of the 405-line recordings before putting things back to where they came from, but next time I'll be sure to upload a photo of it. The picture quality was brilliant, so much so that I'd never have guessed it was being displayed through VHS!

Thanks
'77
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