51
TROUBLESHOOTING GCCO-PP / -PT CONT’D
NO DISPLAY
PROBABLE CAUSE
CORRECTIVE ACTION
Defective Power Switch (-PP
only)
Confirm that toggle switch is getting correct voltage.
Check power switch for normal operation.
Defective Power Switch
output on circuit board
(JP37)
Confirm that JP37 has 5VDC in the off position and nominal voltage
in the on position.
If JP37 has a constant 5VDC check toggle switch for normal
operation.
Defective Control
Transformer
Confirm that 208/240VAC is feeding primary coil.
Confirm that 24VAC and 12VAC is at JP40 (24VAC across solid
yellow wires and 12VAC from one solid yellow wire to yellow with
red stripe).
Defective Display
Check ribbon cable connections.
Confirm that voltage is present at JP40.
If no voltage is present:
Replace control transformer.
If voltage is present:
Confirm that CPU has 5VDC at TP1 (this means that the CPU is
getting correct voltage).
Confirm that CPU has 12VDC at TP2 (this means that the CPU is
sending out the correct voltage).
If no voltage is present:
Replace CPU.
If voltage is present:
Replace display.
Summary of Contents for GCCO-C
Page 29: ...29 GENERAL CONT D ONE PAN TWO PAN THREE PAN FOUR PAN FIVE PAN ...
Page 59: ...59 TECHNICAL DATA CONT D GCCO C TEST POINT LAYOUT TP 2 TP 1 TP 3 TP 4 TP5 TP6 TP7 ...
Page 61: ...61 WIREING DIAGRAM GCCO T ...
Page 62: ...62 WIRING DIAGRAM GCCO AP ...
Page 63: ...63 WIRING DIAGRAM GCCO SII ...
Page 64: ...64 WIRING DIAGRAM GCCO C ...
Page 65: ...65 WIRING DIAGRAM GCCO PP ...
Page 66: ...66 WIRING DIAGRAM GCCO PT ...