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  #16  
Old 12-19-2016, 08:57 PM
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Quote:
Originally Posted by TUD1 View Post
Well I decided to scrap the VFT650 and use it for parts for my PV-1770. The latter had a cylinder drum that was so locked up, it was hard to turn by hand. I took the entire cylinder drum out of the VFT650 and put it in the PV-1770, and it spins perfectly. All the PV-1770 needs now is a couple belts and an idler tire.
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I'd have taken some penetrating oil and tried to free up the old drum first...If a part is nearly shot there is no harm in trying to fix it before changing it.
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  #17  
Old 12-19-2016, 10:38 PM
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I can still do that. The whole drum assembly is still sitting on top of my TV. I just don't have a screwdriver small enough to take it apart.
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  #18  
Old 12-19-2016, 11:26 PM
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No need to take it apart just spray the stuff anywhere where it has a chance to find it's way into the bearings, and places the rotating part touches the stationary part...Manually turn it some, wait 10-15 minutes and try again...PB Blaster penetrating oil has helped me get some pretty stuck parts on my cars and playback mechs unstuck.
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  #19  
Old 12-20-2016, 06:26 PM
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This has to be the easiest VCR in the world to change the idler tire on. The PV-1770 had good fast forward, but no rewind, so I put the idler tire from the VFT650 in there, and now I have strong fast forward and strong rewind. All I need now is the loading motor belt, so I can get play mode back. It tries, but the belts slip and it times out. It's on the way from Studio Sound Electronics.
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  #20  
Old 12-22-2016, 03:31 PM
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Apparently, I'm still not out of the woods yet. I put two new belts on the Panasonic PV-1770. They all work perfectly. The VCR didn't tell me that it had yet another problem in there. Now that it has new belts, it will actually load into play mode 100℅, but I'm not getting the relay click that confirms that the VCR knows it's in play mode. It loads perfectly, no relay click, then it goes back into stop mode. It's doing the opposite of what the VFT650 was doing. I'm thinking it's that durned mode switch. I put the mode switch from the VFT650 in there, and it did NOTHING. I put the original mode switch in there, and it was back to normal. This was a couple days ago.
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  #21  
Old 12-22-2016, 03:42 PM
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Do you know how to look for cylinder servo lock, or close to it? Under a fluorescent light (old magnetic 60 Hz ballast preferred) when it spins up to speed you should see a visible nearly stationary pattern on top of the cylinder from the stroboscopic effect. I mention this because they will shut down like you describe if it detects something dragging the cyl motor down (like a bad tape) making it lose servo phase lock. MAYBE it needs the cylinder servo alignment, but without the service manual I can't tell you which TP# to hook to and pot to adjust. I used to have those alignments memorized I did them so many times.
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  #22  
Old 12-22-2016, 03:48 PM
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Thanks Ed. Speaking of the service manual, I found this bulletin in mine that describes almost the exact problem I'm having. Only my problem is not intermittent. It says the corrective action is to change the belt, and I already did that. It says that if the load is not completed in a specific time, the microprocessor will tell the machine will go into stop mode, which is what it's doing, even though the tape is Fully Loaded.
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  #23  
Old 12-22-2016, 06:05 PM
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OKAY, HERE'S THE DEAL........ The PINCHROLLER is the problem. NOT the mode switch. I actually got it to go into play mode and stay there. When I tried to eject the tape, it was completely crinkled and destroyed. I also noticed that after I took the tape out, the PINCHROLLER was right up against the capstan drive, that's what crinkled the tape. So I move the pinchroller back to the normal position, load another tape, press play, and MANUALLY move the pinchroller over, and it clicked into play mode. So now I have to figure out WHY the pinchroller is so hard to move. I did put a drop of lubrication on it, and it did not help.
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  #24  
Old 12-22-2016, 06:09 PM
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I was going to ask if the pinch roller solenoid was engaging the roller. Maybe the plunger in the solenoid is sticking and needs to be taken apart and cleaned.
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  #25  
Old 12-22-2016, 06:48 PM
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I've never done anything like that in a VCR before. I'll check the service manual and the parts machine and see if I can figure it out.
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  #26  
Old 12-22-2016, 07:36 PM
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How hard is it to move the roller? I've seen top load beta decks where they greased the pivot of the arm the roller is on and the grease turned to glue....Twas so bad on one deck that in trying to remove the arm the pin which was cast into the metal below came out with the arm!
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  #27  
Old 12-22-2016, 07:55 PM
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It's stiff, but it's not too stiff. The VCR has some trouble doing it on its own. I tried it out despite it having the pinchroller problem, and I was very impressed by the picture. The only problem it's having in play mode, is that it loses horizontal sync in forward search and reverse search. Drum slowing down? Here is a video of what the pinchroller is doing.
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Last edited by TUD1; 06-19-2018 at 03:53 PM.
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  #28  
Old 12-22-2016, 09:20 PM
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I swear. For every problem I fix, two more manifest within seconds. Now, it's switching between SP, LP, AND SLP very rapidly, and there is a loud clicking sound coming from the power supply when it does so. On pre-recorded tapes, it doesn't do it, but on ANY tape that I recorded, it clicks between all three speeds very quickly. And don't tell me to clean the control head. I did that three times. If this thing doesn't stop breaking every second, it's about to become dumpster food.
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  #29  
Old 12-22-2016, 11:04 PM
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Update. I just spent the last hour and a half adjusting the audio/control head assembly, and I got it to where it will track perfectly on SP and LP tapes, but it still will not track SLP tapes. It just clicks all around on SP, LP, and SLP. On the plus side, I have never seen a VCR that has a PERFECT freeze frame and frame adavance on SP. The pause is absolutely beautiful with no noise at all. The picture is in pause on an SP tape.
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  #30  
Old 12-23-2016, 09:49 AM
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The control track is on the bottom edge of the tape. That has to have perfect contact, no skewing, no wrinkled edge of the tape. Could be the SLP capstan servo alignment too. In fact I am pretty certain the cap and cyl servo all need alignment being as aged as it is. When people were still bringing them in for service the servos would have drifted off at least a little. Every one that passed my bench got a servo tune-up.

As to losing horiz sync in search modes that is the cylinder servo alignment. On those machines there are separate adjustments for normal and FF REV search modes at the different tape speeds. You need an oscilloscope and service manual to do those alignments.

I looked at the pinch roller video. Looks like it's gummed up not moving freely. It should have some looseness to it when not engaged, and release instantly when the solenoid releases.
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