Creative Engineering ROCK-A-FIRE EXPLOSION - Page 248

check the reading on voltage if you suspect that they are your
source of the problem.
Read the voltage on the red wire in the center of one of the
driver boards with your 'scope. You may also take the large 15
pin molex off the rear of the drawer and read the pins for the
voltage without a load. If you find that the problem lies in the
power supplies either repair or replace it with a new one, see
pages 5-030 and 5-031.
A peculiar problem that may lead you astray has to do with
power supply failure. It may exhibit itself in symptoms like
missing stops or not rewinding or rewinding when it's not supposed
to, but only when in the special deck mode. If this occurs double
check your voltages on your power supply, especially when it is
doing this, try taking a reading on the controller power supplies
and replace them if necessary. Try exchanging power cables first
between bottom drawer and top drawer, they are interchangeable.
C. Character or Props movement problem
General Information
First let us define what we mean by a movement problem. When
a
character or prop movement stays on all the time, or off all the
time, that is a movement problem. It can either be single
movements or multiple ones that are reacting together causing this
problem. In some cases, erratic behavior of movements may be
considered with this section but in the majority of cases erratic
movements can be attributed to either Mechanical or Art related
problems, and occasionally, tape problems. Mechanical or Art
should have already been eliminated and you should instead refer
to the Electronics section on Controller for erratic movements.
Another visually similar problem may occur when either cables
are mixed or air lines exchanged. This could happen when other
repairs are being made or during routine maintenance. A movement
may operate correctly but not in the right time sequence or even
with the correct character. When this occurs, double check all
your cables and air lines to be sure nothing has been installed
incorrectly. Once you have identified the exact problem then
proceed to the proper step.
Long Driver Board
Determine exactly which bit controls the movements you have
in question by examining the bit chart, on pages 5-037 thru 5-064.
Jumper the pin on the Long Driver Board to the chassis and observe
the movement. If the movement activates, then your wire harness
and cables are good. If the bit does not activate, exchange the
board.
Next, check to see if you have 25v. D.C. on the collector
leg of the MJE 800 transistor of the bit in question. Do you have
the 25v. on the transistor leg? If you do, then the problem lies,
most likely with the Solenoid.
Exchange the Long Driver Board from anoth~r slot with the one
you are working on; it may not be necessary to unbolt the driver
boards from the drawer but be careful not to damage the wiring
5-005