5-56 Accessory Troubleshooting
TP-5672 11/95
When the Automatic-Transfer/Manual-Transfer key
switch is in the Manual position, the Not-In-Automatic
LEDilluminates.WhenthesystemisintheManualmode
and is waiting to be transferred to a new power source
after all the time delays have completed timing, the
System-Alert LED illuminates and MANUAL
TRANSFER or MANUAL TO OFF appears on theLCD.
If the system is waiting to be transferred to a new
power source while in the Manual mode, but the
System-Status, System-Alert LED does not
illuminate and MANUAL TRANSFER or MANUAL
TO OFF does not appear on the LCD, connect
TB-DC1-20 to TB-DC1-34.
a. If after grounding TB-DC1-20 the
System-Status, System-Alert LED illuminates
andMANUALTRANSFERorMANUALTOOFF
appears on the LCD when the system is waiting
in the Manual mode to be transferred to a new
power source, Verifly that the
Automatic-Transfer/Manual-Transferkeyswitch
is in the Manual Transfer positionandcheckthe
wiring to the Automatic-Transfer/
Manual-Transfer key switch for an open.
b. If after grounding TB-DC1-20, the
System-Status, System-Alert LED does not
illuminate and MANUAL TRANSFER does not
appearontheLCDwhilethe systemiswaitingin
the Manual mode to be transferred to a new
power source, check the P2 ribbon cable
connectiontothemainlogicboardbyperforming
the following steps.
(1) Remove all power sources.
(2) Wait 30 seconds.
(3) Makingsurenot tobendor breakany of the
pins,removetheP2ribboncableconnector.
(4) Inspect the pins of the P2 ribbon cable
connector.
(5) If any pins are bent, carefully bend them
back. If any pins are broken, the ribbon
cable connector is defective. Replace the
ribbon cable connector.
(6) Carefully reconnect P2 ribbon cable
connector.
If the P2ribboncableconnectionisgood, connectP2-24
to TB-DC1-34. If the System-Status, System-Alert LED
illuminates when P2-24 is grounded, but does not
illuminate when TB-DC1-20 is grounded, replace the
power supply board. If the System-Status, System Alert
LED does not illuminate when P2-24 is grounded, the
main logic board is defective. Replace the logic board
assembly.
Troubleshooting The Manual
Transfer-To-Emergency Source
Pushbutton
When the Automatic-Transfer/Manual-Transfer key
switchisintheManualpositionandthesystemiswaiting
to be transferred to the emergency power source, the
user should press the Manual Transfer-to-Emergency
Source pushbutton.
If the Manual Transfer-To-Emergency Source
pushbutton is not operating, connect TB-DC1-7 to
TB-DC1-34.
1. Check the Manual Transfer-to-Emergency Source
pushbutton and the wires for an open circuit if both
of the following are true:
a. Grounding TB-DC1-7 causes a transfer to the
emergency source when the system is in the
Manualmodeandwaitingtobetransferredtothe
emergency source and
b. Pressing the Manual Transfer-To-Emergency
Source pushbutton does not transfer the power
conversion unit to the emergency source.
2. If groundingTB-DC1-7does not causea transferto
the emergency source when the system is in the
Manual mode and waiting to be transferred to the
emergency source, check the continuity between
P2-1 and TB-DC1-7 following the steps below:
a. Remove power from the logic board.
b. Disconnect the P2 ribbon cable connector from
the power supply board.
c. Using an ohmmeter, connect one test lead to
P2-1 on the power supply board. Connect the
other test lead to TB-DC1-7. If there is an open
circuit, replace the power supply board. If the
resistance is low, the main logic board is bad.
Replace the logic board assembly.
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