BT 2+8, Руководство по установке и обслуживанию

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Faulting and maintenance
Figure 7.1 Faulting flowchart
Start
I
Is the system completely dead?
TPU
1371Issue3(4/91)
yes
I
Power down CCU for
2 seconds then power
up to reset system
I
o/k?
yes no
yes
I
Check mains supply
to CCU
yes
o/k?
no
I
Check fuses
in mains plug
and CCU
I
o/k?
no
I
Change CCU
no
I
Does the fault effect all extensions?
no
I
Change telephone
I
o/k?
yes
no
I
Check wiring
for faults
yes
I
o/k?
no
I
Change CCU
Power down CCU for
2 seconds then power
up to reset system
yes
I
o/k?
no
I
Change CCU
7-2