[f15radar]

Hi all — working through a Sony SLV-R1000 (S-VHS deck w/ built-in TBC) that's got a specific, repeatable fault. Posting here after some bench diagnosis in case anyone's hit this exact combo or knows a good roller source.

SYMPTOMS
- Tape loads and starts to play, then stops on its own a few seconds later (auto-unthreads as if aborting).
- Capture card on the composite/S-Video output shows no picture almost the entire time.
- In the brief window it IS playing, the captured frame tears into misaligned horizontal bands and drops color (B&W only) — see attached stills.

WHAT I'VE CONFIRMED SO FAR (bench testing, not just theory)
Hooked a capture card to the composite out and recorded through several play attempts:
- Threading is healthy — full 180° wrap around the drum, confirmed on video.
- The failure is the pinch roller/capstan losing grip a few seconds in. Both reels stop at the exact same instant (they're capstan-driven, not independently driven), then the deck aborts as a protective measure.
- Pulled the pinch roller: glazed hard and shiny, came off "really really black" with isopropyl.
- Cleaning + light sanding took run time from ~3-14 sec up to 20+ sec before stalling — real improvement, but temporary, as expected. Need to replace it, not just clean it.

STILL OPEN / SECOND-GUESSING MYSELF ON
Sony's mechanical adjustment manual also flags an RKB cam gear timing mark (rotary switch ■ mark vs RKB cam gear ◄ mark) that, if off by a tooth, can independently cause early-abort + blanked video — so I haven't ruled out a second, compounding issue on top of the roller. Also checking the P1 guide's back-tension arm pin (common root cause of the famous "blue gear" failure on this deck) while it's apart.

QUESTIONS FOR THE GROUP
1. Anyone sourced a pinch roller for this specific deck (or the shared SLV-575UC/676UC/R5UC mechanism) that actually fit well? OEM part numbers I've found point to general Sony rollers but I haven't confirmed an exact cross-reference yet.
2. If a fresh roller alone doesn't fully clear it, is the timing-mark/rotary-switch theory above a reasonable next suspect, or does that symptom pattern (tear-to-B&W right before stall) point somewhere else electrically (e.g. video head amp, sync separator) that I should rule out first?

Attaching: 4 stills (noise/torn/clean/blue-LP-mode frame) and a short clip from the capture session showing a full load->play->tear->stall cycle.

Thanks for any pointers.

 

[havok1919]

Hah! Good timing!

I happen to be working through the exact same issue, albeit on a couple of SLV-R5UC decks. The decks had a litany of other problems (power supplies and audio boards failed due to the leaking Elna electrolytic caps), so I'm just now trying to suss out what's going on.

Similar to your description I get the same "tape loads fully, drum spins, starts to play, video appears, but then tape unloads and stops". In my case the video appears clear, but it only shows for maybe ~1 second. I am using an LCD studio monitor that might take a second or so to sync and display though, but for the brief moment I get of video it *looks* good.

I do have the luxury of having two other SLV-R5UCs that I've got going 100%, so I can part-swap pretty easily. I'll try the pinch roller first and see if that has any effect. I did have to replace all the 'blue gears' in every unit I have (100% failure rate in my experience!) so I also cleaned the rotary switch and freed up the RVS Arm assembly as well as cleaned/lubricated the Pinch roller assembly. I suppose it's worth re-checking the gear timing on everything in case I'm 'off by one' somewhere.

I've noticed a fair number of cracked nylon pieces on the MD plate across a couple troublesome decks-- one resulted in the take-up reel wobbling and another crack at the base of the clip on the right side of the reel lock plate was causing that to ride up. I was able to fix the latter by welding the nylon with a low temperature soldering iron, but the one with the broken bushing holding the take-up reel shaft I think will just need to be swapped out with a space from a cheaper 373UC-- that could be a (cheaper) source for pinch rollers as well, albeit used.

There does appear to be some NOS pinch roller assemblies out there still-- and it looks like Sony P/N X-3749-173-4 might be a direct cross to the X3749-770-1. This one didn't seem too crazy price-wise for the whole assembly:

https://www.wagneronline.com.au/product/sony-pinch-roller-1126?sku=vpr200

It's probably also possible just to replace the roller given a few dimensions (ID/OD/height).

Thanks for posting-- you gave me a couple ideas for things to check. Please post your progress when/if you make any!

 

[havok1919]

Update-- I was able to get both of mine going. The fix in my case was to remove the reel deck cover (the flat panel right under the take up and supply reels) and remove/clean/lubricate the pendulum arm (in particular). I also cleaned/lubed the rest of the gears under there, but the pendulum arm was the only one that was clearly stickly/slow to respond.

For science I swapped in the worst, hard, shiny pinch rollers I had and once the pendulum arm was addressed the pinch roller seemed to have no adverse effect. Since I had it on hand, I treated all the pinch rollers with MG Chemicals Rubber Renew (408C) which seemed to do what it claimed. They look much better post-treatment.

After cleaning/lubrication, all the transports seem fine now-- I do have one deck with chroma bleeding (and another with a total lack of chroma) which seems to follow the YC-92 and YC-93 boards. Swapping in a 'known good' YC card stack seems to prove out the transports though, so in my case at least just a fairly invasive/thorough maintenance pass seems to have done the trick.