IBM 3274 51C Maintenance Information page 57

M
6
Map A120 Power Ind. ON
or OFF
PAGE 7 OF 12
029
• Switch power off and reinstall previously removed push pin on
coax panel assembly.
• At logic board, disconnect the OPS panel cable in location
A 1-22 (Feature), A 1-25 or A 1-26.
*J*.
• After power was off wait 15 seconds and then switch power on.
• Measure +5VDC at any card socket 003 pin with reference to
ground (008).
Is the +5VDC missing7
Y N
030
• Switch power off and reconnect the OPS panel cable in board
socket 22, 25 or Z6.
• Replace the OPS panel component card.
Go To Map A100, Entry Point A.
031
• Switch power off and disconnect all the board cables from
board except power cables Y3 and 24.
*J*
• After power was off wait 15 seconds and then switch power on.
Did the power on indicator remaifl off?
Y N
032
• Verify that board cables were in their proper sockets. See
Figure 4-14, and Fold Out (FO-3, FO-5).
• Isolate voltage short to one of the previously disconnected
board cables.
• Reconnect all board cables and cards.
Go To Map A100, Entry Point A.
033
• A board voltage short is indicated, replace board. See Board
Procedure Figure 4-14.
Go To Map A100, Entry Point A.
3-30
MAP A 120-7