Valcom V-119RTHF Instruction Manual page 5

PROBLEM
No Side Tone
No Dial Tone
No Volume to Speaker
No Volume to Phone
Hum Heard at Phone
No Speaker Cancel
R. F. Interference
Crosstalk Between Zones
*Use lineman's test set (Butt set)
TABLE 1
TROUBLESHOOTING CHART
PROBABLE CAUSES AND CORRECTIONS
Check "A" battery connections, polarity and voltage.
Check "A" and "B" battery connections, polarity and voltage
1. Check phone to speaker control.
2. Check* for audio present at tip, ring input BL/WH, WH/BL pair.
3. Check* for audio at signaled speaker pair at 66 block.
4. Check* for audio at input of speaker.
1. Check speaker to phone volume control.
2. Check wiring to talkback speaker.
3. Remove all connections to inhibit pin and verify.
1. Check wiring to speaker.
2. Possible magnetic interference from power supply - relocate unit and
cables at least 18" away.
3. Check for noisy "A" battery.
1. Verify ground present at phone side of at least (2) 10K ohm resistors.
NOTE: Do not apply ground directly to inhibit input.
1. Strap from V-119 chassis to A GND and B GND on punchdown block.
Continue strap to earth or water pipe ground.
2. Connect .05 mfd ceramic disc capacitor from each side of each speaker
pair to B ground on punchdown block.
1. Failure to use twisted pair wiring.
2. Load speaker output pair at block by connect a 1/2 watt 47 ohm resistor
across output pair.
5 947120M