Merlin 3070 Service And Maintenance Manual page 188

WHEN DIAGNOSTICS WILL NOT START
1.
Be sure the system is securely connected to a live ac power
outlet and the power cord is not damaged.
2. Verify that the Power Module(s) is fully functioning:
Make sure the green light on the Power Module is lit.
A.
Place several voice terminals in test mode (slide the T/P
B.
switch to the T position). A tone should sound and the red
and green lights will flash alternately. If no voice terminals
react properly in test mode, the Power Module is defective.
Set On/Off switch to Off and remove the Power Module.
C.
Check for bent or broken backplane pins.
D. Reinsert the Power Module and set the On/Off switch to
On. Check the output voltages of the control unit with a
voltmeter. Measure the digital voltages with respect to
digital ground and the analog voltages with respect to
analog ground. Take these measurements from the
backplane side of the Power Module slot. The table lists
what voltages should be present at specific pins. If any of
the output voltages are not within those listed in the table,
replace the Power Module.
3.
Set the Normal/Test
Wait for the warning
then see if normal call processing is functioning by placing an
intercom call from a voice terminal.
If you cannot place a call and the Diagnostics Module is
installed, remove it. Try to make an intercom call. If you can
complete the call, the Diagnostics Module is probably defective.
Check for bent or broken backplane pins.
Output Voltages of Model 1030 or 3070 Power Module
Pin No. Typical
+5V
056, 156
+5Va
052, 152
045, 145 -4Va
+12V
047, 147
026, 126 -48V
switch on the Diagnostics Module to Normal.
light on the Processor Module to go out,
Minimum Maximum
+5.25V
+4.75V
+5.25V
+4.75V
-4.2V
-3.8V
+12.6V
+11.4V
-43.0V -53.0V
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