TEAC A-3440 Shut-Off Arm problem

[cjacek]

Ok, here's the issue: My TEAC A-3440 plays both Large and Small reels perfectly and seemingly with the same tape tension etc .... BUT I have to play both formats with the "Small/Large" reel button set for "Large" 'cause when I depress it for "Small" (reel), the Shut-Off Arm goes all the way to the right and shuts off the capstan motor. Anyone have an idea what it could be ?

Thanks as always!

Daniel

[The Ghost of FM]

The small/large reel selector switch, I imagine, is setting slightly different amounts of back tension to accommodate for the difference in weight between the two reel sizes.

There might be a servo tension control adjustment pot somewhere inside the unit to adjust this but it might also be a mechanical adjustment on the tension arm itself.

I am only guessing because I don't have a copy of the service manual to study.

I guess so long as it is functional at one of the settings, its not the end of the world, so to speak.

Do you have the service manual, Daniel?

Cheers!

[evm1024]

It is not ready for prime time but you can fins a service manual at:

http://arafel.org/audio/teac-a3440/

Does the right reel stop turning or does it keep turning (but with less tension?)

If it keeps turning then I would look at the adjustement of the Take up torque resister (number 1 on page 13). Adjust the slider as needed.

I'm guessing that because it works with large reels that one of the switch contacts or a relay is bad. this would be a little harder to find. If I come up with a test plan I'll post it later.

the reason of course is because there is not enough torque to pull the tape on the takeup reel and thus the tension is not enough to keep the takeup arm from tripping the safety switch.

Oh, one other thing it could be is the take up break solenoide failing to release ( the take up reel would be hard to turn with the break on )

Regards

[evm1024]

What lever do you want me to get involved in this? (How much help do you want?)

For dibuging I would:

Check out the fuses F905,F906 and F907 (and all fuses for that matter). Of course do this with the back off and the power UNPLUGGED. Could be this easy (But then again why did the fuse blow if so)

Next:

No reels on tables (hubs are ok)

power on
hold up the take up arm with your right thumb
press play (reel tables will both spin)

feel the supply reel table with your left hand
press reel size to toggle between large and small
Torque on supply side should feel the same with both sizes and be "light"

feel the take up side reel table with your right hand
press reel size to toggle between large and small
Torque should be stronger than the supply side torque and should be
stronger with large selected. may be umps when swithcing between them

When toggling between reel sizes you should be able to hear the relay switching inside the deck. The switch makes a lot of noise so listen carefully.

The results of these tests will help us know where to go next.

Regards!

[cjacek]

Thanks so much guys and here's an update: I carefully checked and it is in fact the RIGHT suppy reel that stops whenever I switch to "Small". There is really no need to go all out with the help, evm1024, just enough perhaps that I at least know if this is something I can tweak with minimum of tools. I DO appreciate your help though but please don't go overboard as I don't want to take your time especially if this is not an easy fix by myself.

Btw, I CAN hear all the switching inside whenever I toggle Small/Large.

Again, thanks!

Daniel

PS: GREAT site evm1024! GREAT!!

[evm1024]

Let me know if you hit a snag and I can look/measure something on my A3440.

Regards

[cjacek]

Originally Posted by evm1024

Let me know if you hit a snag and I can look/measure something on my A3440.

Regards

Alright, thank you my friend.

~Daniel

[Vintage TX]

Daniel, on the back of the tension-arm you find 2 switches and also a small spring that can jump loose or be weak.
Check the spring.

[cjacek]

Originally Posted by Vintage TX

Daniel, on the back of the tension-arm you find 2 switches and also a small spring that can jump loose or be weak.
Check the spring.

Hi Rolf, I'll check the spring. Thanks and good to have you back posting here again!

~Daniel