Printronix P7000 Series Maintenance Manual page 266

Chapter 4
Power Supply Operational Check
16. Measure the +48 V test point. It should be 46.0 to 49.6 volts.
17. Measure the+8.5 V test point. It should be 8.1 to 9.4 volts.
18. Release the Push Button.
19. If you must measure voltages again, for each minute you held the Push
Button down, wait at least two minutes with the Push Button released This
allows the Load Block to cool.
20. If any voltage reading is outside of the ranges listed above, replace the
power supply. If all voltages are within range, return to the diagnostic
procedure that caused you to use this tool.
21. Verify that the original problem has been corrected:
a. If the problem has been corrected, go to step 22.
b. If the problem has not been corrected, consider the following:
+48 V Test Point
Monitor Block
Rubber Foot
GND Test Jack: Insert Negative (-) Lead Here
266
This tester applies a small electrical load to the power supply. The
tester load on the +5 volts is about 1.3 amps, so that a printer boot-up
should be possible if the power supply tests OK. However, it is also
possible that a power supply can test OK but still have an internal
problem that prevents it from supporting a full print load. If the printer
still does not print jobs correctly after the power supply has tested
OK:
•
Consider replacing the controller board. If the problem persists,
restore the original controller board, and
•
Consider again replacing the power supply.
+5 V Test Point
+8.5 V Test Point
Figure 22. Testing the Power Supply
NTEMPHI Test Point
Ground (GND) Pad
Push Button: Push to
activate +8.5 V and +48 V
and place an electrical
load on +5 V.