Hi Horacio, I saw your posting in the Mechanical Music Digest.
To help you determine which model you have, go to:

  http://www.player-care.com/system55.html

According to the Pierce Piano Atlas, your unit was made in 1977.
Unfortunately, Kimball never produced a cross-reference which
correlates serial numbers to their various player mechanisms.  And,
the "E" and "F" models are the hardest to distinguish from each other
because the only real difference is printed circuit board in the power
supply.

The Player-Care link that the editors listed is incorrect.  You can
go directly to the Reprints/Technical page at

  https://www.buysecure.com/reprints.html#model-e

If the electric vacuum pump is not coming on when a roll is properly
installed, you might have a problem in the power supply.  However,
first you have to be sure that the roll is properly installed.  In the
modern Kimball players, you must wind the roll onto the take-up spool
at least 1-1/2 turns before you press the Start switch.  If the roll
continues to move when the Start switch is depressed, then you must
trace the A/C line from the vacuum pump back to the power supply.  You
will need a voltmeter to measure the electricity.

Also, you can easily check the operation of the electric vacuum pump
by hooking it directly to 120 volts AC (60 Hz).  That way you can
eliminate the pump as a source of the problem.

Unfortunately, if the vacuum pump does not come on when the start
switch is depressed, the on-and-hold circuits in the power supply
cannot work, since they need vacuum to get activated.

I don't know how the roads are in Argentina, but 1200 kilometers seems
like a long trip, and I would focus my attention on making sure that
the relays in the power supply are correctly seated.  The springs that
hold the movable leaves in place are fairly weak, and one or more of
the leaves might have popped out of position.

In closing, it is extremely difficult to troubleshoot the electronic
circuitry in the modern Kimball players without the aid of the
schematic diagrams.  So again, I would encourage you to purchase the
Service Manual, which sells for $21.00 plus shipping and handling.
The manual also has a section on troubleshooting, which I feel you
will find very useful.

Musically,

John A. Tuttle
Player-Care.com
Brick, NJ, USA