IBM 3274 51C Maintenance Information page 60

B
3
Map A120 Power
Ind.
ON
orOFF
PAGE 10 OF 12
049
(Entry Point F)
Does your machine contain 2 TSR power supplies?
V N
050
• See below Chart A 'Single Power System' and measure D.C.
voltages with reference to ground (008).
CHART A - SINGLE POWER SUPPLY SYSTEM
I I I I VOLTAGE I
I I BOARD I I FROM POWER I RIPPLE *N*
IVOLT I PIN I DC LIMITS ISUPPLY NO.IP-P eM-V)
1-----+------+------------+----------+----------
1+5 IC2003 1+4.6 to +5.51 No.1 I 200 MV
I-----+------+~-----------+----------+----------
1+8.5 IC2B11 1+7.8 to +9.31 No.1 I 340 MV
1-----+------+------------+----------+----------
1+12 IR2S13 1+11 to +13
I
No. 1 I 480 MV
1-----+------+------------+----------+----------
I +24 IF 2B 13 I +22 to +26 I No. 1 I 960 MV
I INote 11 I I
1-----+------+------------+----------+----------
I +24 I K2B 13 I +22 to +26 I No. 1 I 960 MV
I I Note 21 I I
I-----+~-----+------------+----------+----------
1-5 IC2B06 1-4.6 to -5.51 No.1 I 200 MV
1-----+------+------------+----------+----------
1-8.5 IG2007 1-7.8 to -9.31 No.1 I 340 MV
NOTE 1: Measure this point only when machine is
a Model 52-C.
NOTE 2: Measure this point only when machine Is
a Model 51-C.
Were all measured voltages in Chart A within limits 7
Y N
1 1
1 1
N P
051
• If voltage is missing, verify that same voltage is missing at
power supply assembly board plug and repair cable/plug
if needed. See Figure 8-2.
• Replace TSR power supply No.1.
Go To Map A100 , Entry Point A.
MAP A120-10
-N-
The TSR input voltage (+48VOC thru +76VOC) ripple at TSR pin
(+)
E1 to (-) E2 should not exceed 3V. If ripple is a problem.
isolate to capacitor C1 or diode CR-1.
Chapter 3. Maintenance Analysis Procedures 3·33