If anyone has a SONY service manual for the EV C3 model and the U mechanism,
and/or the tiny belts and pinch roller, that they would like to sell, please
let me know.
wb(underscore)wildbill at yahoodotcom

I tried using a small 2-AA battery holder with plain leads to check the tape
loading motor operation of running the guide bloks forward and back several
times, and noticed no resistance to movement or jamming.

Then I made a 3-AA tester "motor exerciser box" using a battery box and a
DPDT and a momentry switch, with clip leads, for easier/more reliable
reversing of the motor, and ran it thru many more cycles with the same
results.
There is no tape in place for these tests, since I would need to have
control of more functions of the Syscon board, such as the reel spindles and
possibly brakes.
I did try putting a rubber band on the guide posts (individually) to add a
little load, but the guide post blocks still operated as they should.

As mentioned earlier, the weird operation is the tape guide blocks running
back 'n forth while trying to unload the tape (before Syscon even activates
Cassette Eject).

It looks as if Syscon can't make up it's mind which way to move the tape
guide blocks to unload the tape.

Unload tape, Start
Starting, OK
Wait a sec, other way
Other way, OK
Uh-oh, wrong way
Huh?
Go back
Going back, OK
No wait, reverse
Reversing, OK
Nevermind, taking too long
Nevermind, OK
Quit now
Quit, OK
Breaktime!
Naptime, OK

As anyone knows that's ever serviced these small machines or camcorders,
it's difficult to run the mechanisms thru the various functions to see
what's happening, if one doesn't have all the various extension cables to
enable the mechanism to run outside of the main unit chassis.

Reel sensors were cleaned? with gas duster, although the interior of this
machine was extremely clean.
Mode switch had a couple of drops of DeoxIT applied, not removed for
examination, although it's probably the next best place to look for
trouble.. damage/wear, dirt or oxidation.
Mechanical load parts have had a minute amout of grease added after cleaning
off excess. The underside of the mechanism appears to be undamaged.
The reel spindles turn freely with the machine off and unloaded.

It looks a little odd, that if I stop one guide post block (with tension on
the rubber band), the guide post block on the other side continues to
travel.. I dunno if that's normal or not.

--
Cheers,
WB
..............