Closer inspection of the transport from the bottom
Now that the PCB is removed, we can have a closer look at the transport from the bottom.
The spooling motor, belt and spooling gear are now clearly visible. We can test the tightness of the belt and can also repeat the same test as before for the spooling gear. We can see the striped bottoms of the cassette reels turning or not as we rotate the gear. These stripes form a feedback to the magnetic sensors that are mounted on the drum control PCB. They sense if the reels rotate when they should and stop the unit when they sense reels don't move when they should. For this reason it is impossible to test the transport in it's current state - although that would be desirable.
At the left edge of the black plastic area the motor controlling tension arms and pinch roller is seen.
Next to it we have the capstan motor. It's the one with the designation U-17B. It is a miniature of the motor's I've seen on my Revox B710 and ultra miniature of the direct drive motor on the Revox TTs, so you understand this motor gained some respect from me
. What didn't help gain any respect is the spooling mechanism that is the source of all the troubles.
To the right of the capstan motor we can see the bottom of the drum motor in the shade.
So, ignoring the mechanised cassette loading and the moving drum, we have a 3 motor DAT transport here. So now you know, 3 motor DAT transports are the cheap, low end versions. The better versions are the 4 motor transports that lose the gears and place one motor under each spool.
We have more work to do now to split the transport in two parts. There are 4 screws to undo. They are anotated with arrows in the pictures. 4 black long screws and 1 brass screw securing the underside of the transport at the front edge of the main chasis.
I recommend that you undo the 4 black screws first and leave the brass screw last.
Once all 4 screws are removed we need to gently lift the undercarriage. And by gently I mean slowly and carefully watching for things that might be thrown out.
OK, this won't happen but there are a couple of spring loaded parts inside and a mishap with a tape might have caused them to jam. In some cases a simple removal of the undercarriage, inspection and reassembly is all that is needed.
When I raised the undercarriage I felt resistance at first - this is why I am giving the advice on going gently. I knew I was not doing something wrong so I continued gently and felt a small snap and the resistance was gone.
I did not see what was jammed but I suspect it has to do with the tension arms as I felt them hard to move by hand and they are spring loaded.