8-2. HOW TO FIND SHORT BETWEEN T-LINE AND R-LINE
If the shorted condition between
corrected for a long time, it may burn out the guard re-
sistor (330
, 1/2W) on the LMU board. Therefore, find
the shorted line according to the following procedure:
1.Turn off the privacy switch on all stations in the system.
2.Turn on the power switch of the system for several seconds, then, turn it off.
3.Watch the lamps on the LMU panels. The lamps on normal lines will go off after approximately 0.5 second. The lamps on the shorted lines will stay on more than 0.5 second.
Power ON | OFF |
| Normal |
Lamp ON | Abnormal |
| |
| (Short) |
Lamp ON |
|
(Brighter | than normal) |
| Lamp goes off gradually |