IBM 3274 51C Maintenance Information page 73

020
MAP A130 I.M. 2400,4800,
9600 Failure
PAGE 5 OF 5
• If possible try running at half the operating speed until T.P.
line is repaired. Note: a reduction to half speed can only be
set at the master modem. See para. 5.4.4 line attachments.
• If problem still exists use your support structure for aid.
021
Were the cards replaced as instructed in Chapter 5, failing
0111 code card chart?
Y N
022
• See Chapter 5 paragraph 5.4.5.6 and perform procedure.
023
• Replace other functional integrated modem cards that were not
indicated to be replaced in card failure chart. See FO-5 for
integrated modem card layout, card locations are G2,
02,
F2,
E2, H2. C2, C4.
• Verify for correct card/board plugging for machine integrated
modem operating speed. See Figure 5-24 and verify card code
on card connector.
• Check integrated modem for loose, not correctly installed or
damaged top card crossover connectors.
Does I
ML
test 0111 still fail?
Y N
024
Go To Map Al00, Entry Point A.
025
• Measure for -8.5 V.D.C. at pin G2 D07.
Is the voltage within the limits of -7.8V to -9.3V?
Y N
026
• If voltage is missing, disconnect plug 1 at power supply No.
2 and verify socket J 1 for -8.5V D.C. on pin 6. Repair
cable/plug pin if needed. See Figure B-3.
• Replace TSR power supply No.2.
Go To Map A100, Entry Point A.
027
• Use your support structure for aid.
3-46
MAP A130-5