GE CT-9800 Technical Publications page 48

GE MEDICAL SYSTEMS
Rev. 9
3-1 Power Checks (Continued)
1) Turn ON the CC1 circuit breaker (bottom rear of cabinet). The blower should begin to operate.
2) CPU Power (S140 and MV7800)
S140 ONLY The Main and Expansion chassis power supplies are functionally the same except the Main
chassis power supply has the capability of activating Battery Back-up (BBU). The MV7800
has no expansion chassis.
CAUTION: Do not power up system without a load on the power supply, CPU for main chassis
and Load Board for Expansion chassis. Powering up without a load on the supply
may cause fuse F5 in the VNR to blow.
A. S140
Note: If your system does not have an S140, skip to step B.
Turn ON the S/140 POWER switch. Verify that the PWR LED on both Main and Expansion chassis are
lit. Refer to Illustration 4-3-3. Look thru any empty slots on the left side of each chassis and verify that the
fans are running.
Locate the three LEDS on the front of the Power Supply Circuit Board as shown in Illustration 4-3-3.
Verify that these LEDs are not lit. If any of the LEDS are lit, refer to Chapter 6 of DG's Field Engineer's
Maintenance Manual, located in the S/140 Manual Volume 1, Part 2, for troubleshooting hints.
(Optional:) Measure the power supply voltages at the test plug, J1, on the front of the Power Supply
Circuit Board as shown in Illustration 4-3-3. Voltage levels should be measured with a
DVM, ripple should be measured with a scope with AC coupling. Pin 9 of J1 should be used
as the ground reference. Specifications are as follows:
S140
VOLTAGE
+ 5V J1-15
- 5V J1-6
+ 12V J1-10
Note: S/140 Power Supplies are switching type supplies. High frequency carrier may be noticed on voltage
signals.
B. MV7800
NOTE: If your system does not have an MV7800, skip to step 3.
Turn ON the MV7800 POWER switch. Verify that the PWR and RUN LED's are ON and the Fans are
operating. The LED's blink if there is a VNR power supply failure.
(Optional): Measure the power supply voltages at the SLOT 0 of the backplane.
S140
PIN MAIN CHASSIS WITH
BATTERY BACKUP
+ 5.10 to + 5.20 V
- 4.9 to - 5.1 V
+11.5 to + 12.1 V
MV7800 MV7800
VOLTAGE
+ 5V A-3,A-4,B-3,B-4
- 5V A-6
5 V.GND A-33,A-34,B-1,B-2
+ 12V B-87,B-88
12 V.GND B-89
ACCEPTABLE LEVEL
EXP. CHASSIS WITHOUT
BATTERY BACKUP
+ 5.10 to + 5.20 V
- 4.9 to - 5.1 V
+11.8 to + 12.2 V
ACCEPTABLE LEVEL
PIN
+ 4.95 to + 5.15 V
- 4.70 to - 5.20 V
N/A
+ 11.70 to + 12.30 V
N/A
4-3-4
CT 9800 QUICK SYSTEM
Direction 18000
S140
TYPICAL
RIPPLE
250 mV P-P
250 mV P-P
750 mV P-P