IBM 3274 51C Maintenance Information page 33

Map A10 BUS TEST.
PAGE 5 OF 5
018
• Switch power off.
• Replace failing TSR power supply No.1.
• Run bus test.
• Reinstall all the cards that were removed and Install card to
card crossover connectors.
Go To Map A100, Entry Point A.
019
• Reinstall all the cards that were removed and install card to card
crossover connectors.
• Inspect for loose operator panel cable in board socket A 1-Z5 or
Al-Z6.
o
Inspect for loose and not correctly installed card to card
crossover connectors. See FO-3 and FO-5.
o
Inspect for loose cables from card in operator's panel assembly.
See FO-7 and FO-9.
Does bus test still fail?
Y N
020
Go To Map A100, Entry Point A.
021
• It is possible to plug card numbers 4, 5 and 6 into the board
backwards. See Figure A-l1.
o
Use General Logic Probe and probe at card No. 12 pin M07 as
you depress the IML push button.
o
Verify that the level HML PB on) goes to down (green) when
button is pressed and goes back to red (up) when released.
(See FO-7 and FO-9).
Is probe point correct?
Y N
022
• Verify for good operator panel cable continuity for plug P2
line (-IML PB on). See Figure FO-7 and FO-9 .
• Replace OPS panel indicator card.
Go To Map A100, Entry Point A.
023
o
Go through this map once more.
Go To Map A120, Entry Point A.
3-6
MAPA10-5