GAI-Tronics 265-001 Intrinsically-Safe Telephone Rack-Mount System - Manual (Page 6)

Pub. 42004-200B
Intrinsically Safe Rack-Mount Telephone System Page: 6 of 13
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02/06
Troubleshooting
This section includes two troubleshooting charts designed to quickly pinpoint the source of problems.
N OTE : It may be advantageous to temporarily connect an I.S. telephone panel directly to the output
terminals of the Model 267 Subrack when troubleshooting. Then, using the charts below, the cause of the
problem should be more easily determined.
Non-Equipment Related Problems
Problem Solution
The I.S. phone is inactive with
no lights on the IBU when the
phone is off-hook. 1. Check the ac power to the Model 266 Power Supply.
2. Check the ac fuse F1 at the Model 266 Power Supply.
The power light is on only when
the phone is off hook. Check for I.S. telephone wiring open.
1. If there is a problem with the ac power to the
Model 266 Power Supply, the IBU lights will be lit in the
following pattern: O =
On , P = Off
ISLOOP
O
LOCK
P
HOOK
P
TELCO
P
2. If the I.S. telephone has a wiring short, the IBU lights will be lit
in the following pattern: O = On , P = Off
(Short may be between conductors, or either/both conductor(s) to
ground/shield.)
ISLOOP
O
LOCK
P
HOOK
P
TELCO
P
3. If the TELCO line has an open, the IBU lights will be lit in the
following pattern: O = On , P = Off
ISLOOP
O
LOCK
O
The I.S. phone has no dial tone.
HOOK
O
TELCO
P
The lights on the IBU flash
randomly. The I.S. telephone has an intermittent wiring short. The short may be
between the conductors or either/both conductor(s) to ground/shield.