IBM 3274 51C Maintenance Information page 56

K
5
Map A120 Power Ind. ON
orOFF
PAGE 6 OF 12
024
• Switch power off.
• At 31 SO. disconnect the 36 pin I/O connector from the file
control card.
*J*
See Figure·E-7.
• After power was off wait 15 seconds and then switch power on.
Did the power on indicator remain off?
Y N
025
• Switch power off.
• Replace card in 31S0. See Figure E.5.7.
• Verify for short in voltage line (+5. +24, -5) in disk file cable.
See Figure C-14.
Go To Map A100, Entry Point A.
026
Does your machine contain a line plate assembly? (See Figure
4-12).
Y N
027
(Entry Point D)
• Switch power off.
• At Type A coax I/O panel assembly disconnect push pin from
terminal E1 (+5V). See Figure 4-10.
*J*
• After power was off wait 15 seconds and then switch power
on.
Did the power on indicator remain off?
Y N
8 7
L H
028
• Switch power off and reinstall previously removed push
pin on coax panel assembly .
• Replace driver-receiver card (isolate to one card, if two Type A
cards are installed).
Go To Map A100, Entry Point A.
MAP A120-6
Chapter 3. Maintenance Analysis Procedures 3·29