Lang ECCO-AP, Руководство по обслуживанию

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38
TROUBLESHOOTING ECCO-C CONT’D
PROBABLE CAUSE CORRECTIVE ACTION
Defective control transformer
(12 VAC).
!
Check transformer for normal operation.
NOTE:
Unplug secondary side of control transformer from CPU before
performing any tests.
CAUTION:
TURN UNIT OFF BEFORE CHECKING ANY RESISTANCE.
!
Check primary coil for 208/240 VAC and 630
Ω
. Check secondary
coil for no less than 10.5 VAC and 1
Ω
.
If voltage is measured on primary:
!
Check for voltage on secondary.
!
Replace transformer.
If voltage is not measured on primary:
!
Check wires for any shorts.
Defective rectifier
!
Check for no less than 10.5 VAC on TP1 and 5 VDC on TP2 .
!
If correct voltage is present at TP1 and present, but low at TP2
unplug both ribbon connections from CPU and re-measure at TP2 .
!
If voltage remains low at TP2 replace CPU (40102-311).
!
If voltage at TP2 increased to 5 VDC when ribbon was unplugged,
plug ribbon back in to CPU and disconnect from Interface board.
!
Re-measure at TP2 .
!
If voltage dropped to below 5 VDC replace ribbon cable (31110-01).
!
If voltage remains at 5 VDC, plug ribbon back into Interface board
and measure for 5 VDC at
TP3 .
!
If voltage is present at TP3 and display is still not on, press and hold
the R/C button on board if LED’s come on replace Interface board.
!
If LED segment does not illuminate or the LED is blank, replace
LED.
At this point you should have a display.