Turning - IBM 3274 51C Maintenance Information

Map A 122 Power On Ind.
is
Off and Fan Not Turning
PAGE 1 OF 6
ENTRY POINTS
FROM ENTER THIS MAP
MAP ENTRY PAGE STEP
NUMBER POINT NUMBER NUMBER
No
entries in this table
001
(Entry Point A)
**********MAP SUMMARY**********
Maintenance concepts for MAP A 122
Entry to this MAP is from MAP A 120 if the Fan is not turning and
the power on indicator is off. When the Fan is not turning this
indicates that input A.C. voltage is also not being supplied to the
input of the power transformer, and thus the power on indicator is
off. When the primary fuse F1 is not blowing this indicates the
A.C. circuit is not complete through power line cord, plug P1
cable, power on-off switch and fuse. The blown fuse condition
can be caused in the primary circuits power transformer, diode
assembly, filter capacitor or the TSR-1 E power supply assembly.
The Fan assembly or 31 SO file motor can also cause the fuse to
blow. Overloads in the TSR power supply voltage outputs do not
cause the fuse to blow, but instead will reduce all voltages to
zero. The MAP concept is to measure for missing A.C. voltage
when the fuse is not blown. If fuse is blowing, replace fuse and
disconnect components until overload condition is isolated.
Note: only use this MAP if the ON-OFF indicator is OFF and fan is
not turning.
• Switch power off.
(Step 001 continues)
3-36
MAP A122-1
EXIT POINTS
EXIT THIS MAP TO
PAGE STEP MAP ENTRY
NUMBER NUMBER NUMBER POINT
2
003
Al00 A
3
006 Al00 A
3
009 Al00
A
3
010 Al00 A
4 014
Al00
A
4 015 Al00 A
5
018 Al00 A
5
019 Al00 A
5
020 '
Al00 A
6 022 Al00
A
6
023
Al00 A