IBM 3274 51C Maintenance Information page 51

Map
A120
Power Problem,
Ind.
ON or OFF
PAGE 1 OF 12
ENTRY POINTS
FROM ENTER THIS MAP
MAP ENTRY PAGE STEP
NUMBER POINT NUMBER NUMBER
No entries in this table
001
(Entry Point A)
This MAP is used to find a power problem when the Power On
indicator is OFF, or to verify that all TSR output voltages are
within limits. When the fan is not turning and Power On indicator
is OFF, this indicates a primary AC voltage problem and MAP
A 122 is used. The output voltages from TSR supply enters the
board through cable sockets Y3 and Z4. Depending upon
machine features, 1 or 2 TSR supplies are used. When 2 TSR's
are used, card sockets A through G receive their voltage from
TSR No.2 and sockets H through V from TSR No.1. NOTE:
Model 52C, sockets are A-H and J-V. The +5 volts is used to
turn on the Power On indicator and is needed from each TSR
supply: When a voltage short or overload condition occurs on any
TSR output voltage the TSR shuts down and all voltages will go to
(Step 001 continues)
3·24
MAP A120-1
EXIT POINTS
EXIT THIS MAP TO
PAGE STEP MAP
ENTRY
NUMBER NUMBER NUMBER POINT
2 004 Al00 A
3
009 Al00 A
3
011 Al00 A
4 012 Al00
A
4 014 Al00 A
4 018 Al00 A
9 043
Al00 A
9
046
Al00
A
5
021 Al00 A
5
023
Al00 A
6
025
Al00
A
6 028 Al00 A
7 030
Al00
A
7 032
A100 A
7 033
A100 A
8
035
Al00
A
8
039
Al00 A
8 040 A100
A
8
037
A100 A
10 051 A100 A
12
055
A100
A
12 056 Al00 A
2 003 A122 A