IBM 5110 Series Maintenance Analysis Procedures page 194

006
Transmit / Receive level
Checkout Map
PAGE 2 OF 6
(Entry Point F)
When the terminal begins to transmit, does
the DB meter indicate the value marked on
the coupler within a tolerance of one db for at
least 10 seconds?
Y N
007
- Set the modem transmit level to the db level
specified on the coupler. If the db value is
not specified, have the customer notify the
telephone company. (NOTE- Some couplers
have an automatic transmit level setting
feature. If this type of coupler is installed,
ask the customer what db level it requires.)
See the BSC M I M for the procedure to set
the transmit level for a 38LS integrated
modem. For IBM external modems, use the
maintenance information provided with the
external modem.
Does the DB meter indicate the correct
level now?
Y N
008
- Disconnect the meter leads from the DT
and DR terminals.
- Disconnect the DT and DR leads from the
coupler that go to the modem.
- Set the db meter switch to the 600
position.
- Connect the DB meter to the white (DT)
and black (DR) wires just disconnected.
Does the DB meter indicate the correct
value now?
Y N
BCD E
t
BCD E
MAP 0831-2
009
Modem problem. Reconnect the white
wire to DT and the black wire to DR at
the coupler.
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.
Bad C2 (38LS) card.
010
Coupler problem. Reconnect the white
wire to DT and the black wire to DR at the
coupler.
Have the customer notify the responsible
person.
011
The transmit level is correct.
Do you want to check the receive level?
Y N
012
The test is complete. If you tested SNBU
and want to test the nonswitched
transmit/ receive levels, go to Step 020
Entry Point B.
013
Go to Page 3, Step 017, Entry Point C.
014
The transmit level is correct.
Do you want to check the receive level?
Y N
3 3
F G
01JAN79
EC 836600 PEC 835541
MAP 0831-2