38Ls - IBM 5110 Series Maintenance Analysis Procedures

E
1
Automatic Answer MAP
World Trade
38lS
PAGE 2 OF 5
005
- Ensure that C2B02 is jumpered to C2D08.
- Redial the data station from a nearby telephone
set.
- Check with a voltmeter (5V ac), C2G 1 0 (Current
Detection 1) and C2G13 (Current Detection 2).
Are both signals pulsing with the ring signal?
V N
3
F
006
- Measure ac voltage at the telephone line.
DANGER
Signal measured can be higher than 150V ac.
Are there ac pulses (ringing current) higher
than 30V ac?
V N
007
Ask the customer to call the PTT
representative.
008
(Entry Point B)
Check with an ohmmeter the telephone
cable(s) from the line box to the wall-mounted
connector. See logic diagram 470.
Is the cable(s) OK?
V N
I
009
Bad telephone cable(s).
010
Bad line box assembly P / N 4836775
C2G 10 and C2G 13 signal levels:
Without ring current
Off: about 1 V ac.
With ring current
MAP 0836-2
On: voltage increases by 0.3V to 1 V ac.
Current Detection 1 signal level can be different /' ' - ,
from Current Detection 2.
~.
,:
DC current up to 48V is present. The voltmeter
must indicate a signal oscillating between 48V
and 78V, and a gap of about 30V ac between
silent and ring periods.
Do not ground one of the telephone wires.
Possibility of a short circuit in the connection.
01JAN79
EC 836600 PEC -------
MAP 0836-2