GAI-Tronics 495-001 Mine Dial / Page Phone Interface Cabinet - Manual (Page 19)

Pub. 42004-198D
Model 495-001 Mine Dial/Page Phone Interface Cabinet Page: 19 of 22
f:\standard ioms - current release\42004 instr. manuals\42004-198d.doc
10/11
Other Faults
If one Mine Dial/Page Phone Station is out of normal service:
1. Substitute known good Plug-in Line Interface card in the appropriate Interface Card Rack, if calls to
that station produce busy or continuous ringing response (instead of “birdie” signal in receiver of
calling station).
2. Substitute known good Mine Dial/Page Phone if calls to that station produce normal response in
receiver of calling station. Before entering hazardous area it may be preferable to test operation to
known good unit temporarily tied across corresponding M
INE P HONE L INES terminals in back of
interface cabinet.
3. Substitute known good Mine Dial/Page Phone in place of regular unit.
4. Check lines between location of Mine Dial/Page Phone and interface cabinet.
If all Mine Dial/Page Phone Stations are out of normal service:
1. Check for presence of dc power to Line Interface Card Racks.
2. Check for blown fuse (F501 or F502) or other defect in the DC Power Transfer assembly. See Figure
10.
If All-Call function does not operate (but switchboard does operate for dialed calls) check operation of or
substitute the All Call/Merge Amplifier assembly.