IBM 5110 Series Maintenance Analysis Procedures page 207

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Manual Call to a Manual Answer
Station using a COT Type Coupler
PAGE 1 OF 2
001
Use this MAP to isolate connection problems
when the local station has a COT (no auto
answer function) type coupler by using a nearby
telephone.
- Be sure the Test switch (if provided) on the
COT type coupler is in the normal operating
position.
- Lift the modem handset from cradle.
Do you hear the dial tone 7
Y N
002
Exclusion key problem in the modem
telephone.
Have the customer notify the responsible
person.
003
- Cradle the modem telephone handset, then
have someone call the local modem telephone
from a nearby telephone.
Does the modem telephone ring?
Y N
004
Telephone problem.
Have the customer notify the responsible
person.
005
- Lift the handset on the modem telephone.
Can you talk with the person on the nearby
telephone?
Y N
A
006
Telephone problem.
Have the customer notify the responsible
person.
©
Copyright IBM Corp. 1979
A
MAP
0833-1
007
(Entry Point A)
- Load MOl
890
from the communications
diagnostic cartridge or the 5110 diagnostic
diskette. E'nter 898 to select the BSC test
patterns. DO NOT enter
0
to select the option
menu at this time. Select step 008 to transmit
continuous SYN characters.
- Lift the Exclusion key. This puts modem
telephone in data mode.
- DO NOT cradle the handset.
Does the nearby telephone hear the
continuous SYN characters?
Y N
008
- Use the ear plug with the CE meter and DB
adapter to listen to the continuous SYN
characters (connect meter leads DT (DATA
TIP) and DR (DATA RING) terminals at the
coupler).
Do you hear the SYN characters?
Y N
2 2
B C
009
Is a N displayed on the reply line of the
MOl display?
Y N
010
Modem problem.
If using an OEM modem, have the
customer notify the responsible person.
If using an IBM external modem, use the
maintenance information provided with
that modem.
011
The routine to transmit the continuous SYN
characters is not running.
Go to Step 007, Entry Point A.
01JAN79
EC 836600 PEC 835541
MAP
0833-1