I suspect the gap on the erase heads is different to R/P heads. I've had a few open circuit heads on various formats. It might be a laugh to take the drum out and inspect the head windings under a microscope. It's possible that the break is visible. Chances of repairing it though are vanishingly small, but there's always that tiny chance that it's in the connection between the head windings and the cables.
Not only is the gap larger but I bet the track width is also slightly wider so it wipes into the guard track area to ensure total video erasure for inserts.
@@12voltvids Oh yes, U-matic was one of the very few video cassette formats to still use guardbands between tracks. Another would be Philips VCR (N1500).
I just got a VO-7600 (simple playback machine, no editing) for $50 on FB Marketplace. It had a fault but it just needed machine oil on one of the shafts. And now it works perfectly. Not an SP model but it looks better than Beta and VHS. So now I have a working archive machine.
In my case, I inspect it using a microscope, but to check the height of the video head, I used a micrometer fixed to the video head. Without this, it would not have been possible.It's amazing what you can do without it!👍
The thing I get scared about 12voltvids is I have so much old audio, and in time with age it's going to fail, some are nearly 40 years old. It's like I only use them rarely. Great channel x wishing u all the best.
Thanks for the video. I always enjoy watching. It’s a shame this one might be a parts machine. It has a lot of hours though. Out of curiosity, where did you find the hour meter? I have a VO-5600 and want to know how much it was used. When I got it, almost 25 years ago, it seemed like it had very few hours. I didn’t add much to it. Thanks!
It's that bottom 2mm on the head carrier,the drum is stepped back from the support so you miss the edge with your cleaning paper ,wet or a felt headed tool may clean the accumulated hard deposit?
@@12voltvids yes I realise on seeing the video to the end now but disable build up of material on the bottom edge of drum and tape is clearly seen to travel over this accumulation.
Hi Dave, I love to learn from each and every video you publish on repairs. I realize you have published so many that I wonder whether you have somewhere an index by Mfr P/N to allow me to find my problem model. On this defective head issue would not you go normally to monitor the RF signal first?. So the head coil appears to be open, why did you not pull the drum and checked the leads to the coil solderjoint? I myself tried to replace a head element from another scrap unit but did not get it aligned properly. There is indeed a limit as how far do we go as a hobbyist
I did go there first. After cleaning I went to the preamp and saw no output. I don't have an escentricity micrometer to set up the drum so I can't change it even if i had the part.
What a sad video, a VT amazing like that in such a condition... Let me ask: even if the drum is wasted, the machine could play a tape with a perfect playng for the sound? I mean, forgeting about the video, we could play/save a audio track?
Perhaps. The audio is after all a linear track, but that's not what is wanted. I'll sell my old playback only machine and who knows what will happen with this. I do have a VO9800 in perfect working order, and if this one is abandoned I'll hang onto it and see if I can make somnething work. For example I do have a working VO4800 portable. I don't know if the drum is compatible or not but it might be worth looking into. Normally I would not consider robbing a part from a working machine, however the portable only accepts the small tapes, so if the drum was interchangable (less the flying erase heads that is) that would be something I would consider as having a machine that accepts both the small and large tapes is better than one that only accepts small. Of course that would only be done on my machine. I would never scrap one of my machines to fix a customers.
Mercury migration. There was a bubble it it that started at 0 and would take 1000 hours at the rated voltage to migrate. Give it half the voltage and it would take 2000. Generally by the time the bubble is all the way to the end the heads are beyond toast.
@@12voltvids I have a JVC BR-7000 which already had that mercury hours meter thingy expired in it when I got it. But it still has the original drum in it, and it performs well. IIRC that one has a 2000h meter in it. And who knows how many hours it ran after the hour meter expired... Anyway, I took the chance when I saw replacement drums for it on ebay for 8 Euros, I bought two of them! They are Japanese made FUTEK drums, I wonder how they compare to the originals performance and lifetime-wise.
Futek was funai technology. The same people that made funai VCRs and they were probably the largest manufacturer of VHS replacement drums. They also made the vast majority of OEM drums for the manufacturer and for that matter they made a huge number of mechanisms that other companies put in their VCRs. Funai was the largest VCR mechanism manufacturer in the world in Japan and they were also The last Man standing. They were the company that made VCRs right to the very end and I know that many people like to bash funai but they actually made a very good machine and many other brands of machines that had other name plates on them actually had funai mechanisms in them. So I would not worry about the quality of the video heads they are top notch I have used them and other brands that they marketed under for years and they always were very good quality upper drums. Samsung was the largest in Korea.
No. Even if it did play the head switching would be in the picture in other words a portion would be snow because the head would be reading the track ahead of the expected position so the vertical sync you be missing. I didn't expect to see a picture just a distorted image but I didn't even see that.
Pg shift can change the switch point by perhaps 5 lines. That's what you occurs at seven lines before vertical sink on VHS and six lines before vertical synchron beta and 3/4. You see the reason why JVC went with seven lines instead of six is so that Sony couldn't say that they stole everything from them even though they did. But with that shift in the location of the head we're talking probably a hundred lines difference. And because it's a head of where it should be there would be no vertical blanking at all therefore the picture would never synchronize if it had been able to pick up signal and amplify the signal it would have been a scrambled mess on the screen I just for shits and giggles wanted to see if there'd be anything that it could pick up but it can't because the track width is too wide for one. All three quarter inch there was a guard band between each track and the flying erase it would not only erase the video track but it would also wipe into the guard track area on either side of the video track to make sure that 100% of the track was erased. so even if the head had been in the correct position it still wouldn't have played back properly. It was just kind of something to do to kill time. If I had an upper drum to try to swap I might tinker around with it even without the eccentricity micrometer fully knowing that it would never be 100% correct again just for something to tinker around with but what I wouldn't do is I wouldn't pull a drum off of a working machine to try to make it work if someone were to hand me an upper drum or an entire drum for one I would swap it if I could get the entire drum I wouldn't have to do any alignment. But I don't think anyone's going to donate one to me so the chances of this machine ever playing back a picture again are pretty slim. It does however give me the opportunity to sell the vp1000 that I've been sitting on for over 30 years to someone who will actually put it to use for archiving which is a good thing because it's not doing me any good just sitting in storage deteriorating. better to put a vintage machine like that back into service for someone who can use it and stick some dollars in my pocket and clear up some space. I got enough 3/4-in machines here for my archiving business to last me as long as I'm going to be doing archiving. I have an NV 9200 Aveo 9800 and a vo4800 portable that all work plus a vp1000 that works perfect and a vp2000 which works but has high mileage. I might drag that one down and do a tune-up on that and unload that one as well as I just don't need all these three quarter inch machines as I see a handful of tapes a year in 3/4. Same with beta SP I have one working beta SP and one that I need to fix but for the number of beta SP tapes I see I really only need to have one working machine.
@@12voltvids Actually, my Sanyo Beta manuals mention 7H before sync, and JVC VHS manuals mention 6.5H. Panasonic manuals mix them up but they usually say 6.5H.
Depends on if you were just using a beta tape. If you were using an EdBeta tape of betacam SP tape then a cleaning tape is a better option as alcohol won't dissolve the metal particles that clog the head.
Just out of curiosity, did you connect both erase heads as playback heads ? No idea if erase and PB heads are physically different but if they are at 180deg and azimuth is correct they should work.
Erase heads are different, likely they cannot be used for R/PB, also one erase head is only in 180 degs angle with the other erase head, so it's a double nope.
They are a completely different gap so I didn't expect anything and that's exactly what i got. Well I could see some signal but nothing that could be demodulated. If you saw the hour meter at the end it's off the scale. High hour machine.
I have and would work on one. They are not much different from regular betamax except have different heads for metal tape. They can use a batecam sp tape.
Shame about the head. Just wondering if you can give any advice, do you know what part of the circuit controls AV in and AV out on the Sony Handycams? I have one that plays a tape fine and outputs video and audio fine but when using AV in which are the same 3 plugs (video plus stereo) from another source then the video and audio work for about 1 minute, I then hear crackling sound then the audio drops out completely but the video is still fine. Leave it off for about 30 min and it repeats the process. Would this be a bad cap or is it controlled by an IC?
@@12voltvids I do have another that works fine but plays Black and White with sound and if I lightly tap the unit the color comes back. Is the color handled on the "video" section of the mainboard?
Good morning from the UK The sun's up everything looks good. Another fantastic video
If only the head was good.
I suspect the gap on the erase heads is different to R/P heads. I've had a few open circuit heads on various formats. It might be a laugh to take the drum out and inspect the head windings under a microscope. It's possible that the break is visible. Chances of repairing it though are vanishingly small, but there's always that tiny chance that it's in the connection between the head windings and the cables.
Not only is the gap larger but I bet the track width is also slightly wider so it wipes into the guard track area to ensure total video erasure for inserts.
@@12voltvids Oh yes, U-matic was one of the very few video cassette formats to still use guardbands between tracks. Another would be Philips VCR (N1500).
I just got a VO-7600 (simple playback machine, no editing) for $50 on FB Marketplace. It had a fault but it just needed machine oil on one of the shafts. And now it works perfectly. Not an SP model but it looks better than Beta and VHS. So now I have a working archive machine.
In my case, I inspect it using a microscope, but to check the height of the video head, I used a micrometer fixed to the video head. Without this, it would not have been possible.It's amazing what you can do without it!👍
The thing I get scared about 12voltvids is I have so much old audio, and in time with age it's going to fail, some are nearly 40 years old.
It's like I only use them rarely.
Great channel x wishing u all the best.
It's all going to fail. Good luck with parts.
Thanks for the video. I always enjoy watching. It’s a shame this one might be a parts machine. It has a lot of hours though. Out of curiosity, where did you find the hour meter? I have a VO-5600 and want to know how much it was used. When I got it, almost 25 years ago, it seemed like it had very few hours. I didn’t add much to it. Thanks!
Left side just in front of where tape elevator sits.
@@12voltvids thanks so much!
It's that bottom 2mm on the head carrier,the drum is stepped back from the support so you miss the edge with your cleaning paper ,wet or a felt headed tool may clean the accumulated hard deposit?
It's not dirty the coil is open.
@@12voltvids yes I realise on seeing the video to the end now but disable build up of material on the bottom edge of drum and tape is clearly seen to travel over this accumulation.
Hi Dave, I love to learn from each and every video you publish on repairs. I realize you have published so many that I wonder whether you have somewhere an index by Mfr P/N to allow me to find my problem model. On this defective head issue would not you go normally to monitor the RF signal first?. So the head coil appears to be open, why did you not pull the drum and checked the leads to the coil solderjoint? I myself tried to replace a head element from another scrap unit but did not get it aligned properly. There is indeed a limit as how far do we go as a hobbyist
I did go there first. After cleaning I went to the preamp and saw no output.
I don't have an escentricity micrometer to set up the drum so I can't change it even if i had the part.
What a sad video, a VT amazing like that in such a condition...
Let me ask: even if the drum is wasted, the machine could play a tape with a perfect playng for the sound? I mean, forgeting about the video, we could play/save a audio track?
Perhaps. The audio is after all a linear track, but that's not what is wanted. I'll sell my old playback only machine and who knows what will happen with this. I do have a VO9800 in perfect working order, and if this one is abandoned I'll hang onto it and see if I can make somnething work. For example I do have a working VO4800 portable. I don't know if the drum is compatible or not but it might be worth looking into. Normally I would not consider robbing a part from a working machine, however the portable only accepts the small tapes, so if the drum was interchangable (less the flying erase heads that is) that would be something I would consider as having a machine that accepts both the small and large tapes is better than one that only accepts small. Of course that would only be done on my machine. I would never scrap one of my machines to fix a customers.
I'm curious how that fuse shaped head hours meter worked is that mercury inside? Almost looks like a thermometer.
Mercury migration. There was a bubble it it that started at 0 and would take 1000 hours at the rated voltage to migrate. Give it half the voltage and it would take 2000. Generally by the time the bubble is all the way to the end the heads are beyond toast.
Here is a video that explains how it works.
ua-cam.com/video/Cxj399LuX1M/v-deo.html
@@12voltvids I have a JVC BR-7000 which already had that mercury hours meter thingy expired in it when I got it. But it still has the original drum in it, and it performs well. IIRC that one has a 2000h meter in it. And who knows how many hours it ran after the hour meter expired... Anyway, I took the chance when I saw replacement drums for it on ebay for 8 Euros, I bought two of them! They are Japanese made FUTEK drums, I wonder how they compare to the originals performance and lifetime-wise.
Futek was funai technology. The same people that made funai VCRs and they were probably the largest manufacturer of VHS replacement drums. They also made the vast majority of OEM drums for the manufacturer and for that matter they made a huge number of mechanisms that other companies put in their VCRs. Funai was the largest VCR mechanism manufacturer in the world in Japan and they were also The last Man standing. They were the company that made VCRs right to the very end and I know that many people like to bash funai but they actually made a very good machine and many other brands of machines that had other name plates on them actually had funai mechanisms in them. So I would not worry about the quality of the video heads they are top notch I have used them and other brands that they marketed under for years and they always were very good quality upper drums. Samsung was the largest in Korea.
There happens to be a used head on eBay. Have you ever tried to wing the alignment? Custom jig?
Have to get the alignment to within a few microns.
Sounds like fun, even with the tool. How long did a replacement normally take?
I could do a betamax with a 3 piece drum in 30 minutes start to finish.
Would it record and playback its own recordings with the flying erase heads in place of the R/P heads?
No. Even if it did play the head switching would be in the picture in other words a portion would be snow because the head would be reading the track ahead of the expected position so the vertical sync you be missing. I didn't expect to see a picture just a distorted image but I didn't even see that.
@@12voltvids Right, and no PG Shifter adjustment would help with that I would guess.
Pg shift can change the switch point by perhaps 5 lines. That's what you occurs at seven lines before vertical sink on VHS and six lines before vertical synchron beta and 3/4. You see the reason why JVC went with seven lines instead of six is so that Sony couldn't say that they stole everything from them even though they did. But with that shift in the location of the head we're talking probably a hundred lines difference. And because it's a head of where it should be there would be no vertical blanking at all therefore the picture would never synchronize if it had been able to pick up signal and amplify the signal it would have been a scrambled mess on the screen I just for shits and giggles wanted to see if there'd be anything that it could pick up but it can't because the track width is too wide for one. All three quarter inch there was a guard band between each track and the flying erase it would not only erase the video track but it would also wipe into the guard track area on either side of the video track to make sure that 100% of the track was erased. so even if the head had been in the correct position it still wouldn't have played back properly. It was just kind of something to do to kill time. If I had an upper drum to try to swap I might tinker around with it even without the eccentricity micrometer fully knowing that it would never be 100% correct again just for something to tinker around with but what I wouldn't do is I wouldn't pull a drum off of a working machine to try to make it work if someone were to hand me an upper drum or an entire drum for one I would swap it if I could get the entire drum I wouldn't have to do any alignment. But I don't think anyone's going to donate one to me so the chances of this machine ever playing back a picture again are pretty slim. It does however give me the opportunity to sell the vp1000 that I've been sitting on for over 30 years to someone who will actually put it to use for archiving which is a good thing because it's not doing me any good just sitting in storage deteriorating. better to put a vintage machine like that back into service for someone who can use it and stick some dollars in my pocket and clear up some space. I got enough 3/4-in machines here for my archiving business to last me as long as I'm going to be doing archiving. I have an NV 9200 Aveo 9800 and a vo4800 portable that all work plus a vp1000 that works perfect and a vp2000 which works but has high mileage. I might drag that one down and do a tune-up on that and unload that one as well as I just don't need all these three quarter inch machines as I see a handful of tapes a year in 3/4. Same with beta SP I have one working beta SP and one that I need to fix but for the number of beta SP tapes I see I really only need to have one working machine.
@@12voltvids Actually, my Sanyo Beta manuals mention 7H before sync, and JVC VHS manuals mention 6.5H. Panasonic manuals mix them up but they usually say 6.5H.
Would you clean heads on an ED Beta machine with alcohol ? I.E AN EDV-9300
Depends on if you were just using a beta tape. If you were using an EdBeta tape of betacam SP tape then a cleaning tape is a better option as alcohol won't dissolve the metal particles that clog the head.
Just out of curiosity, did you connect both erase heads as playback heads ? No idea if erase and PB heads are physically different but if they are at 180deg and azimuth is correct they should work.
Erase heads are different, likely they cannot be used for R/PB, also one erase head is only in 180 degs angle with the other erase head, so it's a double nope.
They are a completely different gap so I didn't expect anything and that's exactly what i got. Well I could see some signal but nothing that could be demodulated. If you saw the hour meter at the end it's off the scale. High hour machine.
Hi Dave, have you ever and or if you haven't, would you ever work on the ED Beta format machines?
Once
I have and would work on one. They are not much different from regular betamax except have different heads for metal tape. They can use a batecam sp tape.
Definitely a beast. Interesting!
If only the head wasn't fubar.
Shame about the head. Just wondering if you can give any advice, do you know what part of the circuit controls AV in and AV out on the Sony Handycams? I have one that plays a tape fine and outputs video and audio fine but when using AV in which are the same 3 plugs (video plus stereo) from another source then the video and audio work for about 1 minute, I then hear crackling sound then the audio drops out completely but the video is still fine. Leave it off for about 30 min and it repeats the process. Would this be a bad cap or is it controlled by an IC?
Switching is done in an ic
@@12voltvids Thanks I did think that since the caps were all replaced. No big deal it plays great otherwise.
@@12voltvids I do have another that works fine but plays Black and White with sound and if I lightly tap the unit the color comes back. Is the color handled on the "video" section of the mainboard?
Haha I was hoping till the end that you will measure the heads.
I was hoping it was just dirty but nooooo open coil. Shit.
27:05 - Seems to use slip rings and brushes there instead of a rotary transformer.
That's just for the flying erase heads there is a rotary transformer for the r/p heads.
To me one of the heads looked pretty much mangled.
That was an erase head that looked off so that wouldn't have affected anything. The head coil is open.
Dead head time to go to bed