MERRICK MC3 90.10.EX, Operation And Maintanance Manual

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MC³ 90.10.EX O&M Manual - 38 -
SOLVING PROBLEMS
If the following procedures do not assist in solving the problem, see Technical Support on page 2
on obtaining factory support for the controller.
Symptoms
Unit does not power up.
WARNING: Only qualified service technicians should work on the controller. When working
with live voltages insure all safety precautions are taken.
Check wiring harnesses, Power running to the controller.
Verify that the fuses are good. There are two (2) fuses in the controller. One (1) is in the power
receptacle and one (1) is on the power supply board.
Using a voltmeter, verify that 110V is present at the power supply.
Verify that the +5 volt and ±12 volts at the power supply are good.
Controller Fails to Boot Up.
If the message "Bad Register Checksum", touch OK to Continue" appears during boot-up, hit OK
and the controller should continue to initialize. After the controller has initialized, check all
settings carefully before operating the Feeder.
By touching the upper left and right corners of the touch screen simultaneously during
initialization, a screen will be displayed requesting "Reset the Registers to Reasonable Values?"
This will set the feeder to the factory defaults that will be different from the actual setup. Re-enter
all of the operating parameters and re-calibrate the feeder before normal operation can resume.
WARNING: Make sure that you check all settings carefully before starting the feeder.
Otherwise, the feeder could operate in an unsafe mode.
LCD Display too dark or too light
The contrast of the LCD display is affected by large temperature changes. It may need to adjust
it. The contrast adjustment (R3) is located inside the controller on the backside of the display
assembly in the upper right hand corner.
The LCD backlight may be burnt -out and need to be replaced. With power applied, there should
be a light seen from the backlight coming from the bottom of the assembly.
No analog Input
Check all wiring; make sure that the polarity is correct.
If at all possible, place a current meter in series with the current loop and verify that current is
present and the polarity is correct.
Check that a positive millivolt input between 0.01 an 1.0 mV exists on the terminals five (5) and
six (6) on the HPAD Board. If it does not exist, the signal source may be damaged or incorrectly
connected.
After correcting the problem, cycle the power to the controller.
External Totalizer problems
Check and verify all wiring and connections are correct.
If the system is using a DC EMT, check the polarity of the connection between the EMT and the
controller are correct.
Check the EMT Parameters on page 25 and verify that the Divide Value and Pulse Length values
are correct for the installation.
No Serial Communications
Check all cables and wire harness. Check the serial port settings in Comm Parameters on page
22.