VCR problem with LP playback

[daamon]

Hi all,

I've had a look around in the forums, but not really sure what to search on so decided to post.

I've recently bought a TEAC 4-head VCR (ex-rental) that records in SP and LP. I could probably provide the product code if that'd help.

Here's my problem: Quite often, when playing back a program that's been recorded in LP mode the playback seems to "drop out" of LP mode and plays the tape at SP speed, resulting in people walking quickly and speaking in a very squirelly voice - most annoying.

I'v tried a number of different cassettes and it's the same. I'd say it tends to happen later on in the tape if that's any help...

What's causing this?
Is it anything a layman like myself could fix?

Any hints / suggestions would be appreciated.

Thanks.

[vhelp]

You did say, ex-rental ?? Just how old is that VCR ??

I remember my very old GE, top load. It had three tape speeds to record in:

* SP
* LP
* EP

If I remember correctly.

And, whenever we recorded a tape at a certain speed (sp/lp/ep) we had to
manualy set the speed, else it would play too fast or too slow. That was how
things were back then. My understanding is like this. You see, back then,
they did not record that tape speed and the VCR would know in advance.

In todays VCRs, that all built-in, and when you play a mixture of "speed"
(sp/ep) the vcr will auto-sense this and play at the correct speed, never to
show slow or fast in the mode.

Perhaps you vcr is an old one, w/out the auto sense feature of todays

-vhelp

[daamon]

Hi vhelp,

Thanks for the ideas...

I don't know how old it is, but it doesn't look like an antique, nor is it showing any signs of age (i.e. battered about etc.).

It definitely has the auto-sense for the tape speed as it mostly works.

The problem is, during playback of a show recorded in LP it suddenly speeds up (as a non-LP VCR playing a LP tape would) - but only for a brief moment ranging to a few minutes, it then plays at LP speed correctly again.

[Roundabout]

If you play that tape in another VCR, does the same thing happen? If not, you probably have either:

A: Bad alignment.
B: Worn or Dirty heads.
C: Tape that was recorded on another machine that was improperly aligned (assuming the machine you have is properly aligned).
D: Problem in the electronics of your machine (unlikely).

[samijubal]

Open the flap on the cassette and look at the tape to see if the bottom edge is crinkled, if so the pinch roller and or the tension band are bad. It's possible that the audio/control heads just need cleaned.

[daamon]

If you play that tape in another VCR, does the same thing happen?

I have another VCR in the house, but it only plays SP mode. I'll try on a friends... Hadn't thought of that.

If not, you probably have either:

A: Bad alignment.
B: Worn or Dirty heads.
C: Tape that was recorded on another machine that was improperly aligned (assuming the machine you have is properly aligned).
D: Problem in the electronics of your machine (unlikely).

B: Buying a head cleaning kit today. Fingers crossed that works...
C: Brand new tapes and used tapes alike, so I'd guess unlikely?

If it's "A", is it easily done by either:
1. Myself (I like to fix things, and it's cheaper)
2. Someone else

Open the flap on the cassette and look at the tape to see if the bottom edge is crinkled, if so the pinch roller and or the tension band are bad. It's possible that the audio/control heads just need cleaned.

OK, I'll try that too. If it's either / or of the pinch roller / tension band, same question as above - is it easily done by either:
1. Myself (I like to fix things, and it's cheaper)
2. Someone else

@ BOTH - Thanks for the info and suggestions. Much appreciated. I'll report back...

[Roundabout]

I've recently bought a TEAC 4-head VCR (ex-rental).

Also the fact that it's an ex-rental unit, God knows what has been done to it, how many tapes it's seen, how many kids jammed peanut butter sandwiches into the loading slot, etc, etc.

Odds are good that the heads are worn and/or dirty. Depending on how dirty, it might need professional cleaning. If it has seen thousands of load/unload cycles, the tape guides could even be loose, the pinch roller and capstan might be so dirty that the tape slips through it, causing it to lose correct speed and sync.

Were the tapes you are trying to play recorded on this machine, or on another?

As you can see, there are many different possibilities that can cause such a problem. It could even be a combination of several different things.

[samijubal]

The audio/control heads can be easily cleaned, don't need a usless head cleaner. Open the unit and clean the stationary head right of the drum with a qtip wet with alcohol. This is the assembly that controls tape speed, either it's dirty or the tape isn't aligned right with the head. Don't try to adjust the head, it's usually the tape that's out of alignment. Look at the tape as it plays and see if it's centered in the guides.

[daamon]

God knows what has been done to it, how many tapes it's seen, how many kids jammed peanut butter sandwiches into the loading slot, etc, etc.

Yeah, hadn't thought of that... When I bought it, it was in bubble wrap and (from the outside) it looks pretty tidy. I'll open it up just to have a look... I may wear rubber gloves...

Were the tapes you are trying to play recorded on this machine, or on another?

Yes, on the same machine that's doing the playback. I don't know if the problem is occurring during recording or playback (I suppose playing it on a friends machine would help to answer that).

@ samijubal - Thanks for the tip. I'll give it a go. I may need to post a picture asking to confirm I'm aiming for the correct component. If I do, it'll be a while as I'm just getting my home PC together so I can then do reading this and fixing at the same time.

@ BOTH - Is it OK to PM you guys if I need to in maybe a week or two to refer you back to this thread?

Cheers...

[samijubal]

No problem on the PM. The audio/control head looks like an oversized cassette deck head.

[furdog]

After cleaning the heads and the tape path, another step (& not a bad idea if tuning up an old VCR) is to replace the drive belts.

Most VCRs have 2 or 3 rubber drive belts which control key parts of tape handling. They stretch with age, and lose flexibility. Unually that is what needs to be replaced when a VCR has tape problems, and the parts are only a few dollars, if you are not afraid of opening the unit, once inside. It is usually not hard to do. I have refurbished my 20 year-old VCR that way.

The problem is finding a store which carries the parts. For example, Cables & Connectors in Connecticut has a complete inventory, including generic equivalents for old models, along with a reference guide to look up your model to find what you need. You could also try a repair operation to see if they could sell the parts, or TEAC, or the internet.

BTW - while not all VCR brands RECORD all three speeds EP, LP & SP - they should be able to PLAY all three. I can remember this coming up years ago. Things may have changed - but did you try the other VCR?

Also - what condition are the tapes in? It might help to fast forward/rewind uninterrupted them multiple times, in case they were unevenly wound on the spools (sometimes a problem).

[daamon]

Hi furdog,

Thanks for the info. I'll try the easiest / cheapest suggestions and work my way through to the more involved ones until I sort it or the unit gets binned.

...but did you try the other VCR?

Not yet. My firend works shofts so may be a few days... I'll report back.

Also - what condition are the tapes in? It might help to fast forward/rewind uninterrupted them multiple times, in case they were unevenly wound on the spools (sometimes a problem).

First noticed on a new tape. Tried another new tape from the same pack - same thing. Tried it on an older (already recorded on) tape - same thing.

[samijubal]

Start with cleaning the audio/control head with a q-tip wet with alcohol.

[Roundabout]

Daamon,

No problem, PM me anytime. If I can help, I'll do whatever I can. VCR's are relatively easy to repair, because the parts are large enough to see them (as compared to some DAT units I've fixed, like the Sony TCD-D7 handheld Digital Audio Tape recorder).

Just let us know whenever you get around to checking all your options and we'll go from there.

@furdog,

You are correct about the SP/LP/EP issue, but that's for NTSC machines. I believe he probably has a PAL unit (he's in Australia), and IIRC, PAL VCR's only record/playback in SP or LP, there is no third (EP) option. Been a while since I fixed a PAL unit, but I think that is true...if anyone knows otherwise, please correct me.

You are also correct on the belts on older VCR's, but most modern VCR's have direct drive capstan & drum motors, no belts. They use gears and friction pulleys to ff/rw the tapes, so you may not find any belts in newer units.

[daamon]

No problem on the PM.

No problem, PM me anytime. If I can help, I'll do whatever I can.

Thanks to you both.

P.S. And, yes, it is a PAL machine. Mine here in Oz only offers SP & LP - it was the same when I was in the UK (PAL too). And I've not seen or heard of any PAL VCRs that do EP, though that's not to say they don't - just unlikely...

I'll get back in the next week hopefully.

[daamon]

Open the unit and clean the stationary head right of the drum with a qtip wet with alcohol.

Would either methylated or white spirit do in the place of alcohol?

[Capmaster]

Open the unit and clean the stationary head right of the drum with a qtip wet with alcohol.

Would either methylated or white spirit do in the place of alcohol?

The best head cleaner was trichloroethylene, but that's off the market. The next best is pure ethyl alcohol, non-denatured, but that's hard to find and expensive. I once bought a 5-gallon drum of it for cleaning our laser optics ..no residue means no power deposited on the lens, and working with a 10kW pulsed ruby laser, that's very important, as it means all the mirrors won't explode when you fire the laser

Any alcohol-based solvent that doesn't leave a residue should work fine. Glass cleaner will also work and won't leave a residue

[daamon]

Cool, cheers Capmaster. Appreciated.

[daamon]

Here's the latest:

1. I opened the unit and it was impressively clean - not even a speck of dust in sight, let alone remnants of peanut butter sandwiches . All looked in good working order.

2. The heads (is that the big silver rotating drum that's on an angle?) looked clean. I have to confess I didn't clean them because of this. I bought some window cleaner as suggested.

3. None of the tapes that are played "too fast" in LP mode are wrinkled at the bottom, or anywhere - they're all perfectly unspoilt.

4. When playing, the tape appeared to be running OK through the guides (the two upright white things that pull the tape around the head...). See Pic 1:



5. I forgot samijubal's warning:

Open the unit and clean the stationary head right of the drum with a qtip wet with alcohol. This is the assembly that controls tape speed, either it's dirty or the tape isn't aligned right with the head. Don't try to adjust the head...

...and cleaned (with the window cleaner) and adjusted the sensor to one side of the head - the one that is on a sprung arm that moves if you push it (see Pic 2 below), otherwise seems fixed in place. NOT the other sensor which is permanently fixed.



This sensor appears to be made of a vertical silver element (see Pic 3 below), and a vertical black element. Adjusting it seemed to do the trick until the symptom came back again later in the tape. But, until then, it was perfect (and so much better than before). I'm guessing these are the audio / control heads as adjusting the various screws affected the audio and the playback speed.



The problem is, I think I've fiddled too much (a very strong suspicion) with the audio control heads as...

a) Recording in LP mode shows that I can only fit 7.5 hours on a 4 hour tape (should be 8).
b) Although recording and playback are now OK - playback of tapes recorded in LP mode before I fiddled are all at fast speed all the way through. So, unwatched programs are hilariously unwatchable.

...resulting in my girlfriend asking why I couldn't "just leave it alone and get a new one?". Fair question...

So - I reckon that the audio / control heads required ever such a slight tweak (as opposed to my heavy handed adjusments on all three screws).

My question...: What can I do to recover this poor abused VCR, if anything?

I'm guessing (hoping) that it'll still be usable as long as I stick to recording and playing back stuff, and just giving up on any recorded programs "pre-fiddle".

Thanks...

[samijubal]

Adjusting the audio head is a last resort, you're in for some fun now. All I can say now is listen to the audio while adjusting the head, when you hear the most treble in the audio, that's when it's close to right. The audio/control head adjustment is very sensitive, may take a very long time to get it right. The guide to look at is the guide past the audio head, see if the tape is centered in that guide, not the guides that load the tape around the drum.

[Roundabout]

Yikes.

It's going to be a bit difficult now to get it back to the way it was, if you don't have a tape path alignment cassette and an oscilliscope. I don't suppose you know anyone with one...hmmm. Didn't think so.

Is there any way you can remember how far you turned the screws, and which ones? Going by the assumption that it was properly aligned to begin with and only just needed cleaning, if you could get it back to where it was before you started it would help.

The drum which you mentioned was clean, is actually quite hard to see if it has been clogged with the naked eye, as the heads themselves are quite small. They are just a tiny chip at the lower part of the upper drum assembly (the rotating part) and there should be at least two mounted 180° apart from each other. To clean them, you should use chamois and not a q-tip or similar, as it can snag on the head and break it.

Other than what samijubal suggested, I don't know of any reliable way to get this unit back into proper alignment easily. The method he suggested is "trial and error", but what else could you do at this point, next to taking it to a tech? (or returning it to where you bought it for an exchange, if that's possible).

I wish I could suggest something beyond that, but once the alignment has been changed, all bets are off. Try the trial and error method, and let us know what you come up with. *crosses fingers*

[daamon]

Yikes

Indeed...

@ samijubal & Roundabout - OK, are you ready for a good chuckle...?

Is there any way you can remember how far you turned the screws, and which ones?

Yes, that's easy - all of them to the full of extent in both directions (i.e. completely tight to removing the audio / control head from the unit to have a look).

OK, I'll pause while you regain your composure and get back on your seats...

After quite a bit of fiddling about - trial and error fitting samijubal's description - (without "a tape path alignment cassette and an oscilliscope" - I've lost touch with my old physics teacher...) I finally got it so that it'd record and playback OK - but only for playback of recordings made "post fiddle". Anything recorded before I tampered still plays fast.

Cheers for the info on what the heads look like and where they're located - I know exactly what you mean. I wondered what those little rectangular holes were...

And I'll also look at the correct guide.

Thanks gents, I'll report back with my next findings and I'll promise not to touch anything...

[Roundabout]

Yes, that's easy - all of them to the full of extent in both directions (i.e. completely tight to removing the audio / control head from the unit to have a look).

OK, I'll pause while you regain your composure and get back on your seats...

Ay-yi-yi!

Well, I guess at least you were able to get it back to more or less the way it was, that's an accomplishment in itself. I would think if you could get it where it plays the older tapes about the same as it was, then you probably have the closest you are going to get to the original alignment. But that still doesn't solve your original problem...unfortunately.

Cheers for the info on what the heads look like and where they're located - I know exactly what you mean. I wondered what those little rectangular holes were...

And I'll also look at the correct guide.

Thanks gents, I'll report back with my next findings and I'll promise not to touch anything...

Just be sure not to use a q-tip to clean those heads (on the drum assembly). It's very easy to break them if you aren't careful, and that'd pretty much be all she wrote for that VCR. You should use chamois, or if you don't have that, even a piece of paper would work better than a q-tip. You have to hold the chamois steady and spin the drum by hand to clean the video heads - DON'T rub up and down! That'll break the heads off for sure. Did you happen to notice if there are more than two heads on the drum? Some VCR's have 4 on the drum.

We used to use what is called a "lapping tape" to break in new heads, and sometimes if the heads were really clogged, the lapping tape would clear them. However, this tape is very abrasive and not sold in the consumer stores (at least I've never seen one there), but it was really effective as a head cleaner. You just couldn't run it longer than a few seconds, because it would wear the heads down right away.

For consumer head cleaning tapes, most of them are crap, so you're left with the manual cleaning method as the most reliable - but also the most prone to damage. So you should be careful.

[daamon]

Ay-yi-yi!

I thought that'd be your reaction - mine too!!!

Just be sure not to use a q-tip to clean those heads (on the drum assembly).You have to hold the chamois steady and spin the drum by hand to clean the video heads - DON'T rub up and down! That'll break the heads off for sure. Did you happen to notice if there are more than two heads on the drum? Some VCR's have 4 on the drum.

Points noted. It was only 2 heads...

Cheers for the info...

[samijubal]

Speed problems aren't coming from the drum, so cleaning the video heads won't do anything to fix the problem. Look at the solder connections on the audio head and see if any of them look bad. You can try unplugging the plug from the main board and plugging it back in, once in awhile they aren't making a good connection. You can try the same thing at the head assembly itself, but it's more delicate and if not careful you could do more damage than good. Your speed problems are at the audio/control head, connections to it, or something related to it since this is what picks up the signal to control speed.

[daamon]

Look at the solder connections on the audio head and see if any of them look bad.

The 3 pictures I posted don't show it, but the connections at the bacl of the audio / control unit looked OK - I made a point of inspecting them.

You can try unplugging the plug from the main board and plugging it back in, once in awhile they aren't making a good connection. You can try the same thing at the head assembly itself, but it's more delicate and if not careful you could do more damage than good.

OK, I'll see if I can give that a go - I did try that (but not too hard coz I'm heavy handed) and it didn't seem to want to come off, that's why I unscrewed the whole unit (D'Oh! ).

I'll have a closer look and a more conerted effort...

Thanks for the suggestions.