eliya
Active member
This is an issue I've had for a while with my machine and I would love some help/pointers. The TL;DR is that whenever I press PLAY, only one motor will have tension, which is to say that it's not spinning. It's usually the take up that has tension and is spinning while the supply has zero torque. Rotating the counter roller (big one on the right) CCW makes the supply motor spin and the take up turn off. Rotating it the other way causes the supply to stop and take up to start spinning again.
The longer version starts with this video showing the problem:
https://youtu.be/us_g_azsE1w
Notice the supply side. There's no tension from the supply motor, nor is the tape tension roller responsive. You can see the tape spilling on that side. When I press REWIND, there's tension on both motors and both tension arms are responsive, but the tape is moving forward instead of back! (Yes, I definitely press REWIND and not FF). Also notice that both tension arms engage when I press STOP.
Not shown in the video is that any adjustments made to the tape tension trimmers do not affect the supply side tension arm.
Another video is showing the take-up motor being unresponsive after I rotate the counter's roller (the big one on the right) CCW:
https://youtu.be/pXiOWHyWSw8
I press PLAY and there's no tension on the take-up side, and the the tape is spilling on the right. BTW, the machine automatically put itself in STOP, I didn't press it. MOT. OFF (tape dump) wasn't accidentally pressed.
This problem can also be shown with no tape: Turn the machine ON. Press PLAY. Only the take-up motor is responsive. Rotate the right-hand roller CCW. Press PLAY. Now the supply is responsive while the take-up isn't. No video of that, but I can easily make one. The difference is that with no tape threaded, pressing REWIND doesn't cause the supply to start spinning.
The electrolytics and tantalums have all been replaced. All the voltages are per what the manual prescribes. I'm not sure where to isolate the problem to, but I'm positive it's with the transport somewhere. It's definitely not with any of the motor control boards. It's safe to say that I've reached a dead end mostly because I don't understand all of the transport's schematic. Any help or even just pointers, or vague ideas, would be absolutely great!
Thanks,
-Eliya
The longer version starts with this video showing the problem:
https://youtu.be/us_g_azsE1w
Notice the supply side. There's no tension from the supply motor, nor is the tape tension roller responsive. You can see the tape spilling on that side. When I press REWIND, there's tension on both motors and both tension arms are responsive, but the tape is moving forward instead of back! (Yes, I definitely press REWIND and not FF). Also notice that both tension arms engage when I press STOP.
Not shown in the video is that any adjustments made to the tape tension trimmers do not affect the supply side tension arm.
Another video is showing the take-up motor being unresponsive after I rotate the counter's roller (the big one on the right) CCW:
https://youtu.be/pXiOWHyWSw8
I press PLAY and there's no tension on the take-up side, and the the tape is spilling on the right. BTW, the machine automatically put itself in STOP, I didn't press it. MOT. OFF (tape dump) wasn't accidentally pressed.
This problem can also be shown with no tape: Turn the machine ON. Press PLAY. Only the take-up motor is responsive. Rotate the right-hand roller CCW. Press PLAY. Now the supply is responsive while the take-up isn't. No video of that, but I can easily make one. The difference is that with no tape threaded, pressing REWIND doesn't cause the supply to start spinning.
The electrolytics and tantalums have all been replaced. All the voltages are per what the manual prescribes. I'm not sure where to isolate the problem to, but I'm positive it's with the transport somewhere. It's definitely not with any of the motor control boards. It's safe to say that I've reached a dead end mostly because I don't understand all of the transport's schematic. Any help or even just pointers, or vague ideas, would be absolutely great!
Thanks,
-Eliya
