Spindle Carriage Alignment; Adapter Power Supply Adjustments - GE CT-9800 Technical Publications

GE MEDICAL SYSTEMS
Rev. 1
3-4 Disk System Adjustments (Continued)
H. Spindle Carriage Alignment
Refer to DG #11, Part 2, for the procedure.
I. Adapter Power Supply Adjustment
Because Data General purchases the adapter power supplies from outside sources, it is possible that more
than one type of power supply may be encountered. Schematics for the various power supplies may be found
in DG #11, Part 5. The potentiometer to be adjusted in each supply must be determined from the appropriate
schematic. The location of checkpoints for the power supplies, and specified limits to power supply voltage
levels may be found in the CT 9800 Quick System Manual, Chapter 4 Functional Checks, Section 3-1. To
adjust the power supplies, it will be necessary to remove the top adapter board which changes the loading on
the supplies. Therefore, the following procedure should be followed:
1. With both boards installed and power ON, measure the +5V and -5V supply at the adapter backplane as
described in Chapter 4, Section 3-1.
2. Determine how much each voltage level needs to be increased/decreased to meet spec, or to reach
+ 5.00V.
3. Turn OFF the power switch on the front of the adapter.
4. Remove the top adapter board and the cover over the power supply.
5. Turn ON power at the front of the adapter.
NOTE: Do not allow adapter to run for extended periods of time with the top board removed.
6. Measure the power supply levels at the backplane again (they will be different from the measurement in
Step 1 because the top board has been removed and the loading has changed).
7. Increase/decrease the voltage levels by the amount determined in Step 2 above. Note that the new
voltage levels will not necessarily meet spec until the top board is reinstalled.
8. Turn OFF the adapter power, reinstall the top adapter board, and turn on adapter power.
9. Measure the voltages at the backplane and compare to the specs. If necessary, repeat this procedure
until the voltages meet specs.
10. When the voltages are within spec., replace the power supply covers.
6-3-22
CT 9800 QUICK SYSTEM
Direction 18000