IBM 6500-V10 Maintenance Manual - Page 260

7. Plug the printer's power cord into the AC power outlet and the printer. 8. Insert the negative (-) lead of the voltmeter into the ground (GND) test jack on the Monitor Block. If the negative lead does not fit into the GND test jack, touch the negative lead to the ground (GND) pad. (Figure 13.) 9. Set the printer's power switch to 1 (on). 10. Touch the positive (+) lead of the voltmeter to the +5 V test point on the Monitor Block. The voltage should be 4.85 to 5.15 volts. (Figure 13.) 11. Measure the voltage at the NTEMPHI test point; it should be greater than 2.4 volts. (Figure 13.) 12. Measure the voltage at the +48 V test point; it should be less than 0.2 volts. (Figure 13.) 13. Measure the voltage at the +8.5 V test point; it should be less than 0.2 volts. (Figure 13.) 14. Press and HOLD IN the Push Button on the Monitor Block. (Figure 13.) 15. Measure the +5 V test point. It should be 4.85 to 5.15 volts. 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: 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. 260