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  #31  
Old 12-23-2016, 09:56 AM
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Okay, thanks. Here is a video of what it's doing. I found that if I press on the control head, it tracks fine, so I looked in the service book and found three A/C head adjustments. I tweaked those, and it still won't track right. VERY Frustrating.
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  #32  
Old 12-23-2016, 11:25 AM
centralradio centralradio is offline
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I'll do as Ed said and check the electro caps in the servo circuit .Some could want dry over the years.
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  #33  
Old 12-23-2016, 11:41 AM
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If it was in front of me, with it in play I would look down at the control head with a flashlight and my little dental mirror to see how the head is aligned, the pickup pole or core should be just barely visible below the edge of the tape. And the audio pole should be barely visible above the tape.


And I assume you cleaned it. Sometimes I would have to use a polishing compound on the AC head to get hardened-on gunk off, especially the older linear stereo VCRs would come in with the L channel muffled and barely audible. No freon or alcohol would cut it. Put a bit of automotive polishing compound on the tip of a wet Q tip and gently going back-and-forth in a horizontal motion I would polish the head.Then clean it with alcohol to remove any of the compound. Audio restored. Same can happen with the CTL track especially since it's on the bottom edge of the tape.
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  #34  
Old 12-23-2016, 12:25 PM
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Everything that Ed and Central said (particularly about alignment), plus:

Quote:
Originally Posted by Ed in Tx View Post
And I assume you cleaned it. Sometimes I would have to use a polishing compound on the AC head to get hardened-on gunk off, especially the older linear stereo VCRs would come in with the L channel muffled and barely audible. No freon or alcohol would cut it. Put a bit of automotive polishing compound on the tip of a wet Q tip and gently going back-and-forth in a horizontal motion I would polish the head. Then clean it with alcohol to remove any of the compound. Audio restored. Same can happen with the CTL track especially since it's on the bottom edge of the tape.
Usually, for those real stubborn cases, iso/rubbing alcohol followed by the usual head cleaner fluid treatment was effective enough in my experiences. I never tried polishing compound but I'll bet that would do great! Wish I could ever have an opportunity to try it!
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  #35  
Old 12-23-2016, 12:37 PM
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Quote:
Originally Posted by Blast View Post
... I never tried polishing compound but I'll bet that would do great! Wish I could ever have an opportunity to try it!
Our audio guy used to keep some on his bench too. Cassette decks in particular with a weak muffled L channel (usually L) and reel to reel decks too with the same.

I remember getting in VCRs the customer had used the wet type cleaner tape in. Would pick up whatever crud before the pinch roller then get rung out at the pinch roller leaving buildup mostly above and below the tape path which would dry on the capstan shaft. Tough stuff to get off without polishing compound.
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  #36  
Old 12-23-2016, 01:51 PM
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What about Blue Magic Metal polish? That's what I polish my vacuum cleaners with.
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  #37  
Old 12-23-2016, 02:05 PM
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Don't know never tried it. If you can polish out plastic or painted surface with it would probably be ok.
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  #38  
Old 12-23-2016, 02:12 PM
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Quote:
Originally Posted by Ed in Tx View Post
I remember getting in VCRs the customer had used the wet type cleaner tape in. Would pick up whatever crud before the pinch roller then get rung out at the pinch roller leaving buildup mostly above and below the tape path which would dry on the capstan shaft. Tough stuff to get off without polishing compound.
Yeah, that makes sense.

Ha! That reminds me of an '83 or 84 Panasonic model I looked at decades ago.

Have you seen/do you remember the spin paint machines at the fairs/carnivals? Where you'd set a plate (or, whatever) on a spinning turntable and squeeze the paint out of bottles? And, the paint would go all over the place including up against the interior walls of the machine?

Well, in this particular VCR there was some kind of white stain all over the inside. Maybe it was a wet cleaner that someone just totally overdosed on. Wherever it was sprayed outward from the upper cylinder. I have no idea what the substance was. But, it was all over the place and at the very same angle as the cylinder! Weird looking.
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  #39  
Old 12-23-2016, 02:27 PM
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Before going all the way with polishing compound, I'd try isopropyl alcohol on a coffee filter. I always kept a stack of coffee filters on the bench, they are often just abrasive enough to cut through gunk that a chamois swab won't touch and they don't leave behind a trace of residue.
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  #40  
Old 12-26-2016, 06:01 PM
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I was factory trained by RCA, Panasonic and several other brands starting in 1978 for like twenty years. I knew the VFT650 like that back of my hand. I'm pretty sure your symptom was a dirty mode switch which I'm sure was a 4 position slide switch which would need cleaning and lube with contact lubricant. In the beginning years, RCA VCR's were Matsushita chassis (Panasonic's parent company) then later Hitachi. As someone said on here, moving a cylinder ass'y to another VCR will require a multitude of adjustments. You would be better off trying to find the mode switch and clean it. The mode switch also had a critical alignment by sliding it when the mounting screw was loosened. Before removing it to clean, etch the chassis metal to mark where it was. If not, it's very hard to get it back in alignment. As far as the seized cylinder motor, you could remove the head and try feeding a drop of fine oil down the shaft where the bearing would be and on the underside as well since you removed it. Be very careful with a video head that has been removed. Those tiny heads are actually on a glass substrate and will shatter !! Larry G
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  #41  
Old 12-27-2016, 10:43 AM
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Okay then. If I had known the PV-1770 was going to have so many problems, I might have just tried to fix the VFT650. But unfortunately, the VFT650 is now strictly a parts machine. I still haven't figured out the pinchroller issue or the poor control tracking in SLP mode. Do you think you can help with that?
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  #42  
Old 12-27-2016, 04:25 PM
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Ok if the servo is stable when you press the tape on the control head that narrows it down quickly to head/tape issue. Take the tape out, release the tape door lock and flip the door up. Is the bottom of the tape creased/furled in any way? If it is the tape is now junk and the problem could be what's called the P5 arm if this model has it. Is there a small arm that comes out to the right of the capstan, between the capstan and where the tape goes back in the cassette? Does it look bent at all? This will cause tape curling. Look with a magnifier at the audio/control head. Is there any kind of wear groove at the bottom of the control head? Then the head is shot. If there is a groove, you can try lowering the height of the head slightly so the groove is a mm or two below the tape. I didn't read back far enough to what kind of pinch roller issue you have. Back when I was doing service those were pretty hardy and didn't cause problems except cleaning . Now I remember some would deteriorate and leave rubber on the capstan which I would scrape off with my fingernails and cleaner. I think the Mitsubishi ones I had to replace but not this brand. Larry G
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  #43  
Old 12-27-2016, 04:53 PM
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Every SLP tape I tried, it would switch back and forth. SP and LP both track fine. I tried moving the head every which way, and I could never get it to track at all on SLP.
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