Samsung OFFICESERV 7100 Service Manual page 121

3.4.5.2 C.O. line Call cannot be Originated
The procedure for resolving the problem that occurs when C.O. line call cannot be
originated is as follows:
Check if the absolute power
between TIP-RINGs exceeds 30 V
in the hook-on status.
Is the power normal?
Yes
When the C.O. line is occupied,
check if RELAY operates by sound.
RELAY operation is normal?
Yes
HOS signal is HIGH?
HOS is HIGH?
Yes
Replace TMC
(LINE1~4: U5, LINE 5~8: U6)
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No
No
Check RELAY control signal.
Check if RELAY control
signal is normal.
Yes
Replace RELAY.
No
Replace C.O. line loop HYBRID.
OfficeServ 7100 Service Manual
Check the power after disconnecting
the C.O. line from the board.
Yes
Power between TIP-
RINGs exceeds 30 V?
No
Repair the C.O. line.
No
Replace TMC
(LINE1~4: U5, LINE 5~8: U6)
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