Panasonic S-VHS HS830 - Broken Video Head?

[collisr]

Hi there,

Here's an effect I've not seen before. Dusted off an old Panasonic HS830 (s-vhs) deck that I had not used before, and before deciding to do too much with it, thought I would try a tape

https://www.youtube.com/watch?v=Pwzpfb6UoJE

As you can see the picture has a great big noise bar at the top (which sometimes rolls to the bottom), a "wobbling" image and uniform noise-like horizontal bars at equal distances throughout the picture. If I hadn't tried multiple known-good tapes, i would have thought it was recorded during a high pressure "tropo-" event.

Cleaned the heads and no change.

Any ideas?

Rob

[Graham G3ZVT]

First thing I would want to do is eliminate the possibility of gross mis-tracking due to one or both inclined tape guides being misaligned.

How well does it play back a recording you've made on it, in its current state?

[John123]

Could be a lazy cap in the power supply or head preamp. Leave it running with a known-good tape and check up on it after an hour or so to see if there's any improvement.

[jayceebee]

I'll also go with a tape guide issue, doesn't look PSU or heads. The machine I believe is fitted with the Z mech and a couple of gears were prone to breaking a tooth or two which meant one or both of the guides weren't fully located into the V blocks.

John.

[collisr]

Thanks John and Graham. I think you're onto something. After laceup, the guides still have some play (backwards) into the V blocks. I'll investigate....

[Welsh Anorak]

You can usually carefully persuade the left guide to locate in the V-block - if that removes the bar you've found the problem. They had odd gears with internal springs whcih always gave the impression of being about to jump out of alignment! Replacing the pair is best -provided you can find them.

[dj_fivos_sak]

That looks like a misaligned tape path. Use a flat-tipped screwdriver and slowly adjust the tape guides until you get a perfect picture and noise-free hi-fi sound. A scope probably needed to bring it to factory alignment.

Fivos

[Maarten]

But never try to adjust until all mechanical defects are either ruled out or repaired.

[boxdoctor]

I would make certain that there is absolutely no dirt or foreign matter preventing the control head being in proper contact with the tape.
It is unlilely that the tape guides have become out of alignment on their own during storage, so I suggest that they should be one of the last things you resort to adjusting, especially if you do not have a proper alignment tape.
John123's suggestion is also very valid, as many electrolytics go low capacity if left un-polarised for a lengthy period of time, causing weird faults to appear, and is an easily done test, too. Tony

[collisr]

Thanks for all the comments. On close inspection it appears one of the drive cogs that completes the lace into the V-blocks is split. To make matters worse, I also managed to split the ribbon cable to the lower video drum during disassembly (doh!) so I think think this machine is going into the spares pile for now.