Sony DNW-A100 Maintenance Manual page 189

2. Unthreading End Mode
Unthreading end mode means that the threading ring rotates in the clockwise
direction, then stops. (It is same state with EJECT completion mode.)
There are two ways of putting the unit into the unthreading end mode without
installing the cassette compartment.
Method 1: Press the EJECT button under threading end mode.
Method 2: Turn the M gear of the gear box assembly in the direction of the arrow B.
M gear
B
TG-4
TG-7
Capstan
Full-erase head
TG-0
Tape cleaner
CTL head
DNW-A100/A50/A45
DNW-A100P/A50P/A45P
TG-9 AT head AT erase head
TG-2 TG-6
TG-1
(Entrance guide)
(S tension regulator)
Unthreading End Mode
5-1-2. Threading End Mode and Unthreading End Mode
TG-3 (Exit guide)
TG-8 (T tension regulator)
Pinch roller TG-5 Slant guide
(Threading roller)
TG-10
5-5