Canon VHS VCR model VR-HF600A

[tvcollector]

Hello, I just picked up one of these Panasonic made VCRS from a local goodwill to ad to the collection. I got it home, and i cleaned the belts some of the seized up parts from the dried up grease, well i got it going great and left it running for quite a while, than all of a sudden i noticed the picture twitching and bouncing, and a bend at the top of the screen along with a flicker. I figured that the tape got misaligned so on the tape transport i loosened and tightened the tensionars, Did no good, and now the HI-Fi stereo doesn't come on, but did when the tape was not playing at normal speed, while messing with the tensionars of course the sound went out when it went into Hi-Fi stereo mode.. I noticed the Hi-Fi tracking shows no bars like it did when working fine, when i switch to check the Hi-Fi on the selector mode.. Also now seeing how i got the adjustment back to where i have a picture, the pause is not clear. Also i notice on some tapes there are three horizontal lines across the top part of the screen, like TVs have when there is a problem with the picture tube.

Anyone have any clues?

[Ed in Tx]

Sounds like it hit a bad place on the tape, and you have mis-aligned it now in an attempt to make it work. Bummer. If it was tracking and playing OK then suddenly wasn't, it is likely some contamination on the tape playing caused this. It won't display a hi-fi signal if it's not tracking properly and/or the hi-fi heads are clogged. The three lines you described are possibly an indicator that it is now far out of alignment. It probably needs a through cleaning and proper alignment with alignment tapes and oscilloscope connected to the head amp RF output. The back-tension band usually needs to be replaced on those, and the back-tension value set with a Tentelometer. I worked on many of those Canons and the Panasonic AG-1800 equivalent back in the heyday.

[waltchan]

Originally Posted by Ed in Tx

I worked on many of those Canons and the Panasonic AG-1800 equivalent back in the heyday.

Really??? I always thought these were the most reliable and durable Panasonic VCRs ever built because they use a linear power supply instead of a switching power supply. These were the only Panasonic Hi-Fi VCRs made with linear power supplies.

[Ed in Tx]

Didn't say they were not good. Indeed they were. But just like anything else mechanical, parts still wear out. Many I've seen come in to the shop not tracking properly with the felt lining from the back-tension band laying down in the mechanism. Worn out pinch roller causing tape skewing was another. And worn out heads. And intermittent mechanism mode sensing switch, and the reel belt. Been probably 10 years since I've seen one so I'm sure I'm missing another common problem or two! We were a Canon and a Panasonic warranty shop so I saw both brands.

[tvcollector]

Too bad you weren't close to me.. The tape i was playing as it started was a tape that i have which i don't use while repairing VCRS, and has no bad parts, so i'm almost positive that the tape is not what started causing the problem, All i know is, I walked away from it for a few minutes and noticed the problem when i went back into the room. I think if i remember correctly the HI-FI at the time the problem accuring was still working, before i went into the machine and started adjusting things.. I find that these Panasonic machines are much harder to work on than the Sony Betamax VCRS. I've done aligning to many of the Betamax machines (The SL-5000 series and Zenith clones) without any alignment tape and manage to correct the same flickering V-hold and bouncing problems. I'm not good with the names of parts, but i know on the Canon I messed with the two guides that have the plastic rollers, that take the tape around each side of the drum, and the plastic wheel on the left, where the tape first goes through before the sensors video and audio heads. Stupid me decides to get the WD40 can out and spray the plastic wheely and ended up spraying too much which than it got on the tape and as it took it to the drum, it got caught up around the drum, and at that time i think is when i noticed the hi-fi stereo started to go out. Since then i cleaned the a/v heads and sensors with contact cleaner and lots of rubbing alcohol. I spend at least 15 hours on the damn thing now.


I notice the power supply on these are different from the other Panasonics as mentioned above, I see it has a huge transformer in it, and you don't hear the arching noise when you plug the VCR into the wall outlet like every Panasonic I've seen.

[Ed in Tx]

You can align a VHS VCR with a known good tape if you know what you're doing. Those entry and exit guides you turned do not go out of alignment by themselves, at least not on Panasonics. (Mitsubishi and JVC had a real problem with those guide rollers getting loose, and I made a good living fixing them but that doesn't apply to the Panasonic made machines). With VHS there are far fewer critical adjustments and alignments than Beta. I worked on plenty of both formats. Unfortunately you have applied the kiss of death - WD40! I remember handing customer's VCRs back to them unrepaired when I would find WD40 sprayed in the mechanism. "It was slipping so I thought I would oil it" or somesuch. Sorry for your loss!

[tvcollector]

I've used WD40 on other VCRS before, i was working on a Panasonic Magnavox Hi-Fi, WD40 got all over the heads, and i was able to fix it. It seems to help with dried up grease, and seized parts along with contact cleaner.. I've aligned the guides many times and i only seem to get them aligned enough to get the tracking position correct, and a picture that bounces and jitters less, i can get the picture aligned to where i first noticed the problem other than the noticeable top three lines, and no Hi-Fi stereo. When i align the right guide in between the drum and audio heads, i notice the sound changes, but sounds better when the picture is not the best. I don't know, am i missing something that i should be aligning too?

Beta VCRS, on the servo board you can adjust the speeds, drum and some other things, and i had to adjust them also when aligning. On Panasonic VHS Servo boards, there are no adjustments for tape speeds, drum, video etc.

[tvcollector]

Update...

I loosened both tape guides to where they are about all the way screwed out, I don't know if thats the position or close to the position they were screwed in factory wise, and now vcr keeps attempting to go into stereo mode with the sound cutting out, (Which i know when not tracking properly sound goes out) it switches back and forth to normal, and sound keeps going on and off, but now there is a steady pulse on the screen with a bouncing motion with it, which makes me believe the drum is not going proper speed, or the tape speed sightly shifts back and forth, also when i adjust the tracking to where it's off track, you can see the off tracking fade in/out at a steady motion with the pulse.

but if i screw in both guides to most the way like i have been doing, and trying to adjust them that way, i don't get the steady pulse, but still i get the same symptoms as i listed above, and vcr never attempts to go into stereo mode.

[waltchan]

Originally Posted by Ed in Tx

Didn't say they were not good. Indeed they were. But just like anything else mechanical, parts still wear out. Many I've seen come in to the shop not tracking properly with the felt lining from the back-tension band laying down in the mechanism. Worn out pinch roller causing tape skewing was another. And worn out heads. And intermittent mechanism mode sensing switch, and the reel belt. Been probably 10 years since I've seen one so I'm sure I'm missing another common problem or two! We were a Canon and a Panasonic warranty shop so I saw both brands.

I actually serviced several of this version. This one was made only for 2 years, 1985 and 1986. I used to own a Canon VR-HF600, like the OP has, Canon VR-HF710, Canon VR-HF720, Panaosnic AG-1810, and Panasonic NV-H70PX. Yes, I agree with you that the felt strip in the tension band tends to slip off easily because of the weak glue applied from the factory, and I always had to re-glue it, but this falling off felt-strip also applies to Panasonic's consumer PV models made in 1984-1985 as well. Worn-out pinch roller is indeed one problem, but the spring that drives the pinch roller loses tension really easily, causing it to wrinkle tapes, even with a new pinch roller. I haven't seen one with a worn-out video head yet, but there is no reel belt inside, unless you mean the cassette carriage belt. There are only 2 belts to drive the mechanism. The 1985 models, including Canon VR-HF600, has a carriage belt, but the 1986 models don't.

The 1986 version is a lot better than 1985 as it omits a carriage belt for better reliability, adds an auto play (when cassette tab is broken), control buttons are located at the bottom left instead at the right side, and the Hi-Fi meter display uses LED separate bulbs for easier reading.

The best model in this series for me is the 1986 Panasonic NV-H70PX because it's full black color, looks like a consumer VCR, and the Panasonic name at the front is more appealing to see than a Canon name at the front (see attached picture of this unit). It is currently my daily-use VCR.

[Ed in Tx]

Originally Posted by waltchan

.. but there is no reel belt inside..

On the AG-1800/VR-HF600 there should be a belt from the capstan motor to the reel clutch pulley. IF I remember right. I guess I could drive over to the old shop, dig out the service manual and verify it. But I won't. Not that big a deal.

I used to replace heads on VCRs, one or two a week at one point. The folks at ASTI Magnetics knew me by first name from all the times I would call in an order for a new upper cylinder head ass'y.

Never had the pinch spring get weak and cause problems, was always the slick, worn out pinch roller.

I do remember the OE Panasonic pinch rollers came complete with the arm and new spring, but after those were discontinued I replaced just the roller on many and that's all it took to fix the skewing problem.

Does testify to the quality of the mechanism in some of these old machines, just replace a few worn parts and good to go for thousands more hours.

[waltchan]

Originally Posted by Ed in Tx

On the AG-1800/VR-HF600 there should be a belt from the capstan motor to the reel clutch pulley. IF I remember right. I guess I could drive over to the old shop, dig out the service manual and verify it. But I won't. Not that big a deal.

I can assure you there is no reel belt use for this chassis at all. 100% guaranteed. I guess it's been a long time for you to remember. Unless you mean to say the idler drive tire or the capstan belt.

This is what the chassis looks like. The company didn't have this one before, but I e-mailed this to the owner three years ago to create a kit for this chassis.

http://www.studiosoundelectronics.com/mbk-121.htm

The pictures came from my NV-H70PX unit. There's 3 belts total for 1985 models, and 2 belts total for 1986 models. It uses two idler tires. The drive tire inside (behind the main idler tire) is the most difficult tire to change ever found in a VCR (much harder than Mitsubishi's 1986-1989 chassis that many technicians claimed).

To change the drive tire, you need to remove the two ring retainers (ouch) to remove the two brakes, then remove another two ring retainers (ouch ouch) again to remove the two reels, then remove one ring retainer for the right reel brake, then you remove a small ring for the drive gear, then you remove a small ring again for the drive idler, then you use a knife (yes) to cut and scratch the old drive tire out (you cannot and it's impossible to remove it out by hand), then you push and squeeze the new drive tire in with your hands by force, and then you put everything back together and put in all the nasty ring retainers again by making sure you don't push it down all the way (or the part doesn't move). If you push it down all the way, you will need to lift the part up to lift the ring retainer up. Sometimes you lift it up too much, and you need to push it down carefully again. It's a very nasty and unbearable process. I wonder what the owner of this website will say about this.

Originally Posted by Ed in Tx

Does testify to the quality of the mechanism in some of these old machines, just replace a few worn parts and good to go for thousands more hours.

Oh yes, especially if there's a linear power supply inside, so they go longer without service. That's the best feature here. If I own one with a switching power supply like all Panasonic PV-model VCRS, it will require more trips to the service (replacing caps, you know) than the one without it.

[Ed in Tx]

Originally Posted by waltchan

I can assure you there is no reel belt use for this chassis at all. 100% guaranteed..

What's the other belt shown in the picture of kit MBK-121? And the other kits shown? They call it the "capstan-idler belt". It goes from the capstan motor to the reel drive idler pulley.

[waltchan]

Originally Posted by Ed in Tx

What's the other belt shown in the picture of kit MBK-121? And the other kits shown? They call it the "capstan-idler belt". It goes from the capstan motor to the reel drive idler pulley.

The "other" belt? Perhaps you mean the tiny belt. This one is the front-loader cassette carriage belt and use for 1985 models only.

[Ed in Tx]

This is the belt I call a reel drive belt, since the reels will not turn without it!

(from the picture with the belt kits)

[tvcollector]

I picked this one up at a local Goodwill store. I had no idea it was Panasonic made until i got it home to put a tape in it, and heard the mechanical parts in it, and said to myself, this is has got to be a Panasonic made machine. I did a research and sure enough. I ended up ruining the original guides, due to not having the proper tool to adjust them, luckily i have a couple of parts machines. The rollers were nicked up and causing the tape to not run smoothly, making the symptoms i mentioned in my last post. I gave up on the damn thing, ive been adjusting so much and now the guides screw in too easy making it hard to adjust. I dont have the glue or anything to make them have a tighter grip.

I find Panasonic machines in these thrifts, very commonly. I'm sure they will start disappearing eventually.