TEAC-144 portastudio repair project

[Dr ZEE]

Dr.Zee.That homemade remote is awesome!!!!!
This looks like a fun project to make if the parts come up.

Yeah , fun, sort of ...
I would not kill 144 just for that, though... it's just happen I had "leftovers" around.
Also, rc-71 is a such primitive (technically speaking) device, that all you need is a box, few push buttons, pair of LEDs and resistors... and just follow the diagram. Well, the connector is a pita, though.

 

[danhl]

Dan,
remove the bottom cover. It's easy.
Then check two small bets 'associated' with tape counter mechanism. See the attached picture, pointed GREEN.
These two belts (BOTH of them!!!!) MUST be nice and tight (so they dont slip). They can be broken, completely melted or just stretched and hanging there.
If that's the case, then you get what you describe.

post an update when you get there. Also check the other belts condition as you are there anyway

Hi

I've checked the belts and all of them seem to be alright. Please let me know if there is anything else I can check?

Thanks a lot! I really appreciate it

Dan

 

[danhl]

Hi

I've checked the belts and all of them seem to be alright. Please let me know if there is anything else I can check?

Thanks a lot! I really appreciate it

Dan

Hi again

Looking at the picture you attached I just realized, that I was missing a metal (magnet?) bolt on top of one of the wheels holdning the belt you asked me to check. I found and replaced it and now everything is working fine.

Thank you so much for your help! The recorder sounds amazing!

Greetings from Denmark

 

[Dr ZEE]

... I was missing a metal (magnet?) bolt on top of one of the wheels holdning the belt ...

Not sure what "bolt" exactly you refering to, but since you FIXED it - it's all GOOD!

In short, the "magnet wheel" MUST spin , varying the magnetic field near the sensor (see attached close up photo of the "machanism" ). If it does not spin - auto-stop gets activated.
Basics of Hall Sensor here at Wiki, link: http://en.wikipedia.org/wiki/Hall_effect_sensor

********
glad you've got your studio running again

 

[danhl]

Not sure what "bolt" exactly you refering to, but since you FIXED it - it's all GOOD!

In short, the "magnet wheel" MUST spin , varying the magnetic field near the sensor (see attached close up photo of the "machanism" ). If it does not spin - auto-stop gets activated.
Basics of Hall Sensor here at Wiki, link: http://en.wikipedia.org/wiki/Hall_effect_sensor

********
glad you've got your studio running again

It was exactly the magnet wheel I was referring to. Thanks for the pics and the link!

Regards
Dan

 

[ruuud]

hi guys,

i'm reviving this thread because i'm repairing a similar teac 144. these pics and explanations really help, but the machine i'm working on has transport issues and i was wondering if anyone here can help. i've ordered a belt set from ebay, and replaced the capstan belt. the capstan now runs fine. the smaller belt for the reel tables mechanism wasn't in the package, but it is running too. however, the 2 belts for the tape counter are both there, but not running and neither are the two spools when i use the transport of play functions. any idea why the spools aren't running when the motor pulley is?

i have replacement belts for the tape counter ones, but how do you get to them? does the mechanism have to come out all the way?

thanks for any tips!

ruud

 

[ruuud]

self update #1: you can get to the counter belts when you remove the top cover and the bottom cover. replace the small one first, and then the bigger one that leads to the cassette spool.

 

[Dr ZEE]

ruuud,
so did you get it spinning? It (the counter) has to spin to "PLAY"-operate, or the machine will go to "STOP" mode shortly after.

 

[ruuud]

i haven't gotten around to plug it back in yet.. i took the whole thing apart according to your excellent guide and cleaned all the gunk from the faders, pots, etc. i'm now putting it back together.

i found that it helps to slide out the board with the pots if you unscrew 3 screws on the chassis and take off the metal back panel that holds the in- and outputs on the back. and i'm having a hell of a time getting those 3 plastic self locking pins back in.. ;-)

 

[ruuud]

i've put it all back together. everything works, but just. capstan belt is fine, reel table mechanism belt also seems good and runs. the counter belts and counter are also working.
however, there is a lot of added noise when the machine plays. it's weird, at first it seemed to have a strong pull in play mode, then it suddenly lost that. ffwd goes okay until about 3/4 of the tape, then it stops, and rew barely works at all. i looked, and it seems the problem is with the wheel with the red dot on it that's inside the mechanism. against this runs another wheel via direct contact with a rubber belt only around the wheel, and that seems to be slipping...

 

[Dr ZEE]

....there is a lot of added noise when the machine plays. it's weird, at first it seemed to have a strong pull in play mode, then it suddenly lost that. ffwd goes okay until about 3/4 of the tape, then it stops, and rew barely works at all. i looked, and it seems the problem is with the wheel with the red dot on it that's inside the mechanism. against this runs another wheel via direct contact with a rubber belt only around the wheel, and that seems to be slipping...

uhhhhhhhhhhh, sounds like you've got the "situation" on hands

see attached picture (I don't have any better shot )

(If you look through a magnifying lense): The surface of That little rubber "tire/shoe" (not sure about correct technical term for it ) is (should be, that is) actually not flat but rather like a "micro-gear", and so is the "plastic hub", so the rubber "shoe" and the plastic hub should mate-lock like gears.

So when that rubber goes old and bad it gets flat and will slip. You get noise, lose FF/RW power, and may not be able to play, as the take up "reel" will not spin fast/strog enough or even stop spinning completely and you get AUTO-stop kicking in in the middle of play.

I had that situation. The only way to fix it is to find another 144 for parts or just that part that is still good and replace that rubber shoe.
Also it's a pain in the a%% to do without completely disassembling the transport block (which I don't recommend) - DON'T DO IT!!!!! - it's IS REALLY hard to put it back together as hundred of small parts will be all over the table. heh heh...
I 've managed to replace that rubber shoe by first cutting the old one with aven knife reaching it through the hole and it comes off.
Then I used long curved nose surgical clamp to slip the "new" shoe back onto the pulley.

I don't think TEAC-parts dep. still has those parts available. Or am I wrong? I may be wrong. I have no idea really.

best regards and good luck

 

[ruuud]

yes, that's where the problem area is.. actually i thought it was the rubber on the wheel behind the one you describe, the bigger one that is driven from the smaller wheel attached to the one you describe. that rubber 'tyre/shoe' in my 144 actually still has some relief on it, you can see the 'gears' but it isn't much.

i have had contact with tascam US about 2 fader caps for the 144, and they actually have those in stock. so they may have this belt too, the only problem would be a part # or actually an accurate description..

we'll see how it goes, i'll ask some tascam/teac specialists.. i'm only restoring this thing more or less for fun, i have other proper reel to reel recorders for music to record on. thanks for the insights!

 

[ruuud]

well, i've been pretty unsuccesful in trying to find a replacement. as i don't have the room to save it as a 'doorstop' an because realistically it's too heavy to sell as a broken thing, i've decided to part it out so other users can at least enjoy some donor parts from this machine. i'll post the ebay links here when i'm done taking pics and dismantling it..

 

[xxmangoosexx]

Since we are talking 144, i thought i'd drop a line with a question:

my 144 works pretty well, but it has two quirks:

1) I sometimes hear a weird electronic buzzing/oscillation noise through mixer channel 1. Not really sure anything can be done about that at this point! But thought i'd see if anyone else gets a temporary buzz (that isn't too loud) but only happens every 25 seconds or so.

2) When in PLAY/RECORD, if i hit STOP the transport stops, but the heads don't fully disengage. I have to hit REW/FF to get the heads to fully come off the tape, and then hit STOP. Anyone else have this kind of problem?

 

[guyburns]

Edit
After a few hours playing around, I discovered why Rewind was not working correctly. There are two grub screws that hold the rubber wheel, X, (see below) to the spindle. They had come loose. Thus the rubber wheel would spin but the spindle would not (very hard to see that it wasn't spinning), and the spindle was therefore not driving the cassette. This was easily fixed: the grub screws could be accessed with a screwdriver without having to remove anything except the back cover.

The Problem
I have a Portastudio 144 which has an intermittent problem with Rewind. Play and Fast Forward work well, but Rewind stops and starts as if something is slipping; and when it stops for more than about a second, it then cuts out.

WHAT THE PROBLEM ISN"T
1. The problem does not appear to be connected with a lack of drive due to a worn "toothed" drive wheel. The rubber wheel (call it X) on the Rewind spindle driven by that toothed wheel turns as it should, but if I apply slight pressure to the segmented black plastic bit (call it Y) in the cassette housing, the part that actually turns the cassette, Y will stop. All the while, X keeps spinning. It's as if there is slippage between X and Y. When I do the same for Fast Forward, there is quite a large amount of torque available.

2. The problem does not appear to be connected to loose "counter" belts or a problem with the magnetic disk and Hall Effect sensor. I say that because Play and FF work perfectly.


WHAT THE PROBLEM MIGHT BE
I'm pretty sure that something is slipping in the shaft that connects X & Y, but I can't see how that can be as I assume it is actually a solid shaft connecting the two.

Any suggestions most appreciated.


DOCUMENTATION FOR DOWNLOAD
Also, while I have been refurbishing my three Tascams (144, 234 and 414) as a part of digitising all my recordings, I have also digitised all the paperwork that came with the machines. To download schematics, owner's manuals, and brochures for the three machines mentioned, and also a detailed instruction guide on replacing the capstan and cam belts in a Tascam 234, as well as other audio goodies, go to ***

Note: this site won't let me post the link. If someone who has more than 10 posts can gmail me at gdburns, I will send the link to you, and I would appreciate it if you could then post the link. Thanks.

 

[Sexy Heather]

I recently acquired a 1980 Teac Portastudio 144, myself:

It needs a couple of new fader knobs, a push button cover, a bulb and a belt. Otherwise in great shape for 33!