Teac V-1RX Two Questions

[Wigwam Jones]

First, I decided to take the plunge and try to replace my drive belt on my Teac V-1RX. I bought it new in Okinawa, Japan, in 1983. I'd like to put it back in service.

I got the top off. I had an earlier thread there I noted that the cassette door was 'locked' and I could not get it open. Someone told me how to revolve the top pulley until it unlocked, which I did, and it opened. Yay.

Now, after some time, I finally had a spare moment so I put it on the table and opened it up again. I saw the old belt had simply stretched. And by peering closely inside the deck, I saw I could remove it without actually removing any part of the drive. So far, so good.

Since I have not yet ordered a belt, I looked around and found a rubber band. Yes, I know, this is not a suitable replacement, but I just wanted to see if it would go around. It does.

However, when I power the deck on, the big pulley on top rotates, going 'click, click, click, click,' etc. The door locks and won't open again. None of the functions work. I put a cassette in and pressed play and the heads started going up and down, up and down, up and down, and the big pulley was going around going click, click, click. I powered it off, rotated the big pulley around again until I could unlock the door, and took the tape out.

So...two questions.

The first is, what the heck is going on here?

The second is, where should I order a new drive belt? I looked in the old threads, but the comments that I could find date back to 2005 and a lot of dead links. So if you have a company that you've dealt with recently that's still in business, please feel free to recommend them.

Thanks!

 

[GasMan]

First of all, Congratulations! he V-1RX was one of TEAC's better units. The belt is called "Belt, Reduction Pulley" and is listed as part # 5800106800 in the V-1RX service manual. The same system was used in all of the TEAC "V" family decks and also in the Tascam 122 Mk.II pro deck. I'd look up belts for a 122 Mk.II on E-Bay and that would work. I got one recently for my 122 and it only cost a couple bux.

How did you replace the broken belt without removing the drive mechanism? Kinda tight in there. I usually remove the four screws that secure the mechanism in the deck, slide it back enough to clear then lift and roll it on its back. That gives clear access to the three screws that hold the mechanism control motor. When re-assembling, the only semi-critical thing is getting the little "forked" knob on the sensing pot lined up on the center rib of the control cam. That's what tells the motor when to stop. The other thing that comes to mind is that the rubber band may not be rigid enough to act as a belt and is slipping back causing the mechanism to "hunt" constantly. My best advice is to get a proper belt and your problem should be solved. really is a very durable design. Mine is 30 years old and has had only the belt replaced yet still keeps on going.

 

[Wigwam Jones]

First of all, Congratulations! he V-1RX was one of TEAC's better units. The belt is called "Belt, Reduction Pulley" and is listed as part # 5800106800 in the V-1RX service manual. The same system was used in all of the TEAC "V" family decks and also in the Tascam 122 Mk.II pro deck. I'd look up belts for a 122 Mk.II on E-Bay and that would work. I got one recently for my 122 and it only cost a couple bux.

Thank you, I will do that.

How did you replace the broken belt without removing the drive mechanism? Kinda tight in there. I usually remove the four screws that secure the mechanism in the deck, slide it back enough to clear then lift and roll it on its back. That gives clear access to the three screws that hold the mechanism control motor. When re-assembling, the only semi-critical thing is getting the little "forked" knob on the sensing pot lined up on the center rib of the control cam. That's what tells the motor when to stop. The other thing that comes to mind is that the rubber band may not be rigid enough to act as a belt and is slipping back causing the mechanism to "hunt" constantly. My best advice is to get a proper belt and your problem should be solved. really is a very durable design. Mine is 30 years old and has had only the belt replaced yet still keeps on going.

It did not look like the rubber band was slipping, but I guess it's possible. It seemed more as if the mechanism had lost some sort of internal synchronization, as if gears were no longer meshing as they should, if that makes any sense. I'm not saying that's what happened, just what it seemed like.

I was able to squeeze the rubber band in (and the old drive belt out, which was stretched but not broken) by sliding it carefully past the nylon 'thing' in the middle (looks like a cam of some kind) that is in between the bottom pulley (motor) and the top pulley. There's a very small clearance there, just enough to squeak the belt (and rubber band) past.

I'm sorry to say I don't know which screws you're referring to. There are so many. "The four screws" that hold the unit in don't really seem to mean anything to me. I see dozens of screws and have no idea which hold it in and which don't. Sorry to say it's quite confusing to me.

I'll order a new belt and hopefully that will fix the problem, but honestly I am thinking the problem is not that; the snapping noise it is making is not good at all, and I don't think it is related to the band. But I could be wrong.

 

[Wigwam Jones]

Update: I ordered the belt (actually two of them, just in case). I will advise when they arrive and we can see what goes on with the weird 'out of synch' problem it seems to be having. Thanks!

 

[hdrobien]

Remember me ?

I think that the positioning pot (the one which is "clutched" in the large black wheel), near the cam motor, is either dirty or misaligned causing wrong information being sent to the microprocessor.

Maybe this occured when you tried to slide the rubber band past the "nylon thing" (the clutch ?).

 

[Wigwam Jones]

Remember me ?

I think that the positioning pot (the one which is "clutched" in the large black wheel), near the cam motor, is either dirty or misaligned causing wrong information being sent to the microprocessor.

Maybe this occured when you tried to slide the rubber band past the "nylon thing" (the clutch ?).

Maybe so. How do I fix it?

 

[hdrobien]

First you can check if the white nylon thing is properly "clutched" in the large black wheel. See if there are other possibilities in term of positioning.

Then you can inject Deoxit in the potentiometer itself, which is located under the small green circuit board (red circle) and turn it a dozen of time so the liquid can penetrate.

 

[Wigwam Jones]

First you can check if the white nylon thing is properly "clutched" in the large black wheel. See if there are other possibilities in term of positioning.

Then you can inject Deoxit in the potentiometer itself, which is located under the small green circuit board (red circle) and turn it a dozen of time so the liquid can penetrate.

I checked the white nylon thing. It spins around fairly freely, I am not able to detect any difference in performance based on what direction the flipper on it points. I removed the two screws holding the circuit board down and I removed the wiring harness clip from the back of it, but I cannot remove the circuit board itself, so I can't flip it upside down. I do not want to force it and possibly break it. I do not know which direction to push, pull, or otherwise prod it. Does something else have to be removed first?

I also pulled the four screws that allow the entire transport mechanism to be moved backwards slightly. This is of no particular help, because it does not change the position of the white nylon thing, so there is still only a tiny gap between it and the wheel it apparently meshes with. That means no real room to put the new belt on without stretching it to make it thinner, which I'd prefer not to do. So I'm still at a loss how to mount the new belt properly. Removing the transport screws did not appear to offer any advantage.

And finally, while I was in there looking around, I noticed a large rubber-coated wheel behind the cassette well that appears to have turned to black goo. I carefully touched the tip of a blade screwdriver to it and it pulled away with black tar-like goo on it; the wheel appears to have dissolved into tarry icky goo. How does one go about replacing that wheel? Is it a part one can obtain from other decks? I ask because I've had a search on eBay for v-1rx decks for years and never see them.

Thanks!

 

[hdrobien]

I checked the white nylon thing. It spins around fairly freely, I am not able to detect any difference in performance based on what direction the flipper on it points. I removed the two screws holding the circuit board down and I removed the wiring harness clip from the back of it, but I cannot remove the circuit board itself, so I can't flip it upside down. I do not want to force it and possibly break it. I do not know which direction to push, pull, or otherwise prod it. Does something else have to be removed first?

If what you call the white nylon thing is the white part that appears in my red circle above, it should be clutched (meshed ?) with the big black reel.

I also pulled the four screws that allow the entire transport mechanism to be moved backwards slightly. This is of no particular help, because it does not change the position of the white nylon thing, so there is still only a tiny gap between it and the wheel it apparently meshes with. That means no real room to put the new belt on without stretching it to make it thinner, which I'd prefer not to do. So I'm still at a loss how to mount the new belt properly. Removing the transport screws did not appear to offer any advantage.

As said before you have to remove first the 4 screws that holds the entire mecanism. As far as I remember 2 are under the case, 2 above the mecanism. Then you flip the mecanism to have a better access to the rear. For that you have to gently push the mecanism backward to have clearance, and then flip. No need to disconnect anything but to cut some ties. Finally you have to remove the metal plate that holds the motor and the small green circuit with the positionning pot and the nylon thing (?). You will have a clear access to put the new belt. When reassembling be sure to clutch properly the nylon thing with the big black reel.

And finally, while I was in there looking around, I noticed a large rubber-coated wheel behind the cassette well that appears to have turned to black goo. I carefully touched the tip of a blade screwdriver to it and it pulled away with black tar-like goo on it; the wheel appears to have dissolved into tarry icky goo. How does one go about replacing that wheel? Is it a part one can obtain from other decks? I ask because I've had a search on eBay for v-1rx decks for years and never see them.

This is the idler wheel (and tyres). Its purpose is to link the motor to the reels during play, fast forward and reverse. I had to replace mine with plumbing rubber seals. To remove this part you just have to remove the 2 screws that hold the assembly on top of the mecanism and pull it backwards.

Once more, look at my pictures here:
http://forum.vintage-audio-laser.co...tat-une-platine-cassette-teac-1rx-t7708.html?

 

[Wigwam Jones]

Thanks, I'll look at it again. I did not try to 'flip' the unit over. I noted that the wire bundles running to it from various directions seemed to hold it pretty tightly in place - I did remove the four screws you mentioned. I'll try the flipping over thing.

The white nylon thing is definitely not 'clutched' with the big black wheel. There is a very small gap between them; that is how I got the rubber band I was experimenting on in the first place, and how I got the new belt on. The gap is very small, but it is there. No clutching going on, unless the white nylon thing is meant to retract, in which case it is currently retracted.

 

[Wigwam Jones]

Another question - there is a fellow selling 'Tascam 112, 122, etc' idler tires on eBay. Might those be a fit for this unit, do you happen to know? It's only five bucks if so. Since the belt for the 122 Mk2 was the same, I had some hope that perhaps the idler wheel might be as well? Thanks!

 

[hdrobien]

Thanks, I'll look at it again. I did not try to 'flip' the unit over. I noted that the wire bundles running to it from various directions seemed to hold it pretty tightly in place - I did remove the four screws you mentioned. I'll try the flipping over thing.

You have to cut some ties on wires to get clearance.

The white nylon thing is definitely not 'clutched' with the big black wheel. There is a very small gap between them; that is how I got the rubber band I was experimenting on in the first place, and how I got the new belt on. The gap is very small, but it is there. No clutching going on, unless the white nylon thing is meant to retract, in which case it is currently retracted.

Strange because it doesn't retract and the white nylon thing must rotate with the big black reel. Could you take a picture ?

 

[hdrobien]

Another question - there is a fellow selling 'Tascam 112, 122, etc' idler tires on eBay. Might those be a fit for this unit, do you happen to know? It's only five bucks if so. Since the belt for the 122 Mk2 was the same, I had some hope that perhaps the idler wheel might be as well? Thanks!

I don't know. You should measure your tires and check. Another optio is to get the service manual for both decks and check similarities.

 

[Wigwam Jones]

You have to cut some ties on wires to get clearance.

I will do that, thanks.

Strange because it doesn't retract and the white nylon thing must rotate with the big black reel. Could you take a picture ?

Yes, but it will have to be at the weekend. I will post once I have them, thanks again. FYI, when I rotate the big black wheel, the little white nylon cog does not seem to rotate with it. I may be missing the movement since I have not flipped the unit over and hence cannot see very well down inside, but it doesn't look like it is moving anyway. Perhaps the piece broke somehow, but I didn't see any shavings or broken pieces inside the unit when I opened it. Very nice and clean in there.

 

[Wigwam Jones]

I don't know. You should measure your tires and check. Another optio is to get the service manual for both decks and check similarities.

The seller says they can do any size idler tires, but they ask for either the ID and OD or the part number. They mention part numbers:

112 Series P/N: 06-0112
112 MK II P/N: 06-1130
122 Series, C-3X P/N: 06-0122
122MKII Series P/N: 06-0112
122MKIII Series P/N: 06-1130
234 Series P/N: 06-1123
244 Series P/N: 06-0244
246 Series P/N: 06-1123

If I knew the part number for the V-1RX, I would send that to the seller, but I've never seen a technical manual for that model online.

 

[hdrobien]

Notice that the cog itself must be "clipped" on the specified part of the black reel (see red circles).

 

[Wigwam Jones]

Notice the the cog itself must be "clipped" on the specified part of the black reel (see red circles).

Thanks again, I will look once I get it upside down! I really appreciate the help and the photos! :thmbsp:

 

[Capwinder]

I have two V-1RX cassette decks and have replaced the control belt in both. First some general notes. The Idler Wheels generally do not have to be replaced. They only are used for fast forward and reverse functions. Keep in mind the capstan is direct drive on these units.
The drive mechanism must be removed from the chassis to gain access. Remove the two screws on the top, two screws on the bottom, the big white connector at the back of the mechanism, the fragile cassette well light, some wire tie downs and you can carefully lift the mechanism up out of the chassis. You can only lift it so far though because many wires will still be attached to the circuit boards.
The black wheel is known as the control wheel and it has alignment marks on it for the stop, play, forward and reverse functions that should line up with the indicator when everything is working properly. The indicator is a pointer that is actually formed right out of the chassis sheet metal. The service manual details all of this in a diagram. I refer to the plastic white component sitting within the control wheel and attached to the potentiometer as the yolk. Like the yolk on a cow it's fork goes on both sides of a raised spoke of the control wheel so that it moves in both directions as the control wheel rotates. This moves the potentiometer and as a result the unit knows where the control wheel is positioned. The control wheel is a cam. A roller rocker arm follows it to move the head assembly up and down and position it properly for fast forward, reverse, and stop.
The potentiometer has a lock nut on it and you can loosen it and then push the potentiometer up enough to slide the belt under the yolk fork and around the pulleys. I do not loosen the potentiometer bracket. Make sure the fork in the yolk is properly positioned on top of and on both sides of the control wheel spoke during reassembly.
This is a good time to adjust the damper if the cassette door is opening too quickly. It is critical to NEVER, EVER lubricate the damper with anything! Turning the screw in slows the door opening speed. Just do a little at a time. You should have a cassette in and the clear door cover on the opening frame because the weight will affect the opening speed. Also it's a good time to clean the heads and the pinch roller.
Hope this helps, good luck with your repairs.