Teac X-1000R Runaway tape in fast rewind mode

[GEARTECK]

My Teac X-1000R, when rewinding the tape will go into runaway mode. When the stop button is pressed it totally kicks into high speed (runaway). If the rewind button is pressed during runaway the tape speed will reduce to normal rewind speed but there is no way of stopping the tape with out shutting the deck off. I have accessed the deck, check and cleaned all connections, the problem remains. This will happen when you function the return to zero button as well, no other function will pull it out of runaway. If I unplug the Rec and play ampl PCB from the power/servo PCB assy.., basically take the counter out of the picture the deck will rewind and fast forward at a very high speed but will stop when the stop button is pushed. But with the counter in, rewind is off and running. This problem happens as soon as the rewind speed reaches normal speed. If you hit the stop button before the deck completely winds up to normal speed it will stop the rewind direction but not as quick as it should. There is a longer wind down time before the breaks set verses the fast forward wind down time. All other functions work as they should.
Has anyone else run into this or does someone have an idea where I should look from here.
Thanks!

[Tim]

I have successfully repaired this exact defect more than once for my customers, but it was so many years ago that I'm a bit unsure now what I did.  I'm pretty sure though that if you perform a complete play-mode and fast-wind mode tape tension regulator set-up (as described in the service manual) that the defect will disappear.  You need a Tentelometer to do this, BTW. 

If you want to play "technician", though, carefully mark the where the play tension and fast wind tension pots are set to and just experiment with settings.  Start with fast wind pots. Even if you manage to fix the defect, a full set-up (done properly) is highly recommended.

[GEARTECK]

Thanks Tim, I will give it a try!

[GEARTECK]

TIM,
Thanks a million for the tip on the deck runaway problem. I did what you said, accessed the service manual and checked out the set up section on the deck. Since I wasn't having trouble with the play modes, forward or backwards, I basically got on the fast rewind pot and gave it a little tweaking. I don't have a tentelometer, but will be keeping my eyes open for one. As far as the tape tension, I basically watched the tention arms on both the fast forward and rewind modes as I held the opesit reel and initiated the wind modes. I checked for the same amount of lift, also went by feel of the reel pull, applying pressure with touch as supply reel was being pulled. Both spools had an equal amount of tape on them during this test. The problem has seemed to dissapear. May have been a little crud in the pot, who knows. But I have control back on the rewind and return to zero mode. Everything seems to be working fine! I have it playing right now as I'm writing this post!!

THANKS AGAIN TIM! YOU WERE A LIFE SAVER!

GEARTECK