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[email protected] capnjacksparrowsavvy@gmail.com is offline
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Default Sony SVO-5800 Jamming (Left Shuttle and Back Tension Arm BlockEach Other)

On Saturday, April 14, 2012 3:37:14 PM UTC-4, wrote:
On Apr 14, 10:04*am, Mike S wrote:
Hi,
I'm a total beginner, but I have a pretty simple VCR issue that doesn't appear to be covered in Sam Goldwasser's VCR FAQ (http://www.repairfaq.org/sam/vcrfaq.htm) or David T. Ronan's Practical VCR Repair, based on the skimming I've done.

When I'm stopping or ejecting a tape, my back tension regulator takes too long to move out of the way, and the left shuttle assembly gets blocked on it - and pins it in place - on its way back to the front of the VCR. *Basically, the two parts end up jamming each other, so neither can move, and it screws up the timing of the two shuttles as well as the gears underneath slip teeth.

What exactly is the mechanism that is supposed to make the back tension arm retract away from the full erase head and toward the tape door? *Is it supposed to sit passively while the left shuttle assembly pushes it back toward the front, or is the VCR supposed to apply power to explicitly move it out of the way? *If the VCR is meant to explicitly apply power, what controls the timing of this?

I half-expected this issue to be a common cause of jams and thoroughly covered by VCR repair resources, since the back tension arm literally crosses the path of the left shuttle assembly, but I haven't found anything about it yet. *I can't imagine I'm the only person in the world who has ever had this happen to them.

My VCR has other issues that bring about this behavior initially, but this is the most pressing problem due to the potentially damaging nature of a jam like this and the difficulty of removing tape afterwards. *(Usually the VCR will work fine...but using my VHS-C adapter revealed a problem with the source spindle. *After an initial error occurs, the machine stops. *After cycling power again to eject, it jams the shuttle and back tension regulator...and once that happens, it breaks down on playback and jams on every eject attempt until it's "fixed." *I "fixed" it once before by magic and got it working again with regular tapes, but trying the VHS-C adapter again caused the jam once more, and I'm trying to understand what's going on this time.)

Thank you for your time!


Sony broadcast tape transports have issues with lubricants drying
out / thickening up which causes problems similar to yours. The cure
is to disassemble the component, clean out the old junk and re-
lubricate. Since their lubricants were bad to begin with I don't use
Sony lubes. Nye Oil II is a vastly better light machine oil. A 2 oz.
bottle is about $9. Sony SGL grease can be subbed with Nye Rheolube
363F but that stuff is expensive. Do NOT use Lubriplate as it's even
worse than SGL as it separates. And whatever you do do NOT use WD-40
for ANYTHING in electronics.



Thank you! I have the service manual, so I'll look into which parts need lubrication, and I'll use Nye Oil II as you suggest.

Nevertheless, the back tension arm does not appear to be particularly resistant to movement: I can move it very easily with my finger when it's not jammed, and the only resistance I feel appears to come from the spring...it just happens not to retract on its own when it counts. Do you know whether it's meant to retract actively (powered by electricity) or passively (pushed back to the front by the left shuttle assembly)?