Main Power Supply Troubleshooting Flow Chart Procedures; Power Supply 24V Out Test; Short Circuit Test - GE LOGIQ E9 Service Manual

D 5180483-100, R
IRECTION
7-9-4-5

Main Power Supply Troubleshooting Flow Chart Procedures

Use these procedures with the Troubleshooting Flow Chart to isolate cause/failure(s).
7-9-4-5-1

Power Supply 24V Out Test

Power-down the LOGIQ E9. Turn off the rear panel Main Power Switch. Wait for the ON/OFF Button
LED to turn OFF. Unplug the MAINS Power supply cable from the Power Supply and the on-site MAINS
Power System.
You will need to make DC voltage measurements with a DMM on the 24V pin, Z 22 of connector P4, on
the Power Supply. See: Figure 7-159 "Main Power Supply P4 Location and P4 Pins Location
(reference)" on page 7-209. Disconnect the Main Power Supply from the Backplane connectors, leaving
all the other cables connected to the Power Supply. If you are unable to get the probes of the DMM into
pin Z 22 on P4, you may need to insert some longer (non-braided) wires into the pinholes so that they
extend far enough upward for you to make the measurements with the DMM probe. To do this, you may
also need to disconnect the remaining cables on the Power Supply so you are able to view and locate
pins Z 22 and ground pin Z 28 on P4 and insert the wires. Once the wires are in place, you MUST
reconnect all cables that were removed.
With the Power Supply still disconnected from the Backplane and all other cables connected, power-up
the system. Once the system has gone into simulator mode, measure the DC voltage between pins
Z 22 and Z 28 (ground). If the nominal voltage measured is between 23V and 25V, then this test passes.
If the voltage measured is not within that range, the test fails.
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Short Circuit Test

With the system powered-down and the rear panel Main Power Switch off, disconnect the Power Supply
from the Backplane. Remove the BEP I/O to Backplane cable from the BEP.
Use a DMM to measure resistance (ohms) to test for electrical isolation between the 24V rail and
ground. Measure the resistance between the 24V pins of the Backplane and the ground pin. If the
resistance is low - less than 10 Mega ohms, then there is a short circuit in the Backplane. Replace the
Backplane and go to the beginning of the Short Circuit Test.
If there is no short between the 24V pins and ground, then go to the next step.
Measure the resistance between the TC-3 pin and the ground pin of the test connector. If the resistance
is low - less than 10 Mega ohms, then there is a short circuit in the I/O Board. Replace the I/O Board
and go to the beginning of this step. If there is no short found, go to the next step.
Reconnect the BEP I/O to Backplane cable. Measure the resistance between the TC-3 pin and the
ground pin of the test connector. If the resistance is low - less than 10 Mega ohms, then there is a short
circuit in the BEP I/O to Backplane cable. Replace the cable and go to the beginning of this step.
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PROPRIETARY TO GE
. 7
EV
Section 7-9 - Troubleshooting Tips
LOGIQ E9 P
ROPRIETARY
S M
ERVICE ANUAL