AKAI - Take-UP motor and Supply motor
when I found, that my GX-210d has very low tension in F.FWD or RWD mode, I read and compared some service manuals of 3 motors AKAI R2R:
And I found, that AKAI developers made many test on this trouble (not possible to make a flat tape "cake" on reel in fast rewind modes).
And that engineers tuned a schematic with reel motors 24XO-2 and changed critical resistor R3 (12 ohm - in GX-210D - U=100V , 43 ohm - in GX-230D - U=120V etc.)
The problem is this : in fast rewinding modes is on most AKAI very very low tension and is not possible to well wind the tape on Take - Up reel.
Have You some experience with it ?