HP LaserJet Enterprise M608

Overview

Startup sounds are heard when the printer power is turned and is operating correctly. If these sounds are heard, the dc side of the power supply is functioning. If startup sounds are heard, the next troubleshooting step is to isolate print engine, formatter, and control panel problems. Perform an engine test. If the formatter is damaged, it might interfere with the engine test. If the engine-test page does not print, try removing the formatter, and then performing the engine test again. If the engine test is then successful, the problem is almost certainly with the formatter, the control panel, or the cable that connects them.

NOTE:
Depressing, and holding down, the test-page switch causes the printer to continually print test pages. Releasing the switch stops the test page continuous printing.

Troubleshooting power on problems

1. Verify that power is available to the printer. If the printer is plugged into a surge protector or uninterruptible power supply (UPS), remove it, and then plug the printer directly into a known operating wall receptacle (make sure that the wall receptacle provides the correct voltage and current for the printer).
2. Try another known operating wall receptacle and a different power cord.
3. Listen for startup noises (for example, fans or motors) and look for illuminated lights on the control panel and formatter LEDs.
   NOTE: Operational fans, motors, and control-panel lights indicate the following:
   • AC power is present at the printer.
   • The power supply is providing either or both 24 Vdc and 5 Vdc voltages.
   • The DC controller microprocessor is functioning.
4. Check the following:
   a. Turn the printer on, and then listen for startup noises. If normal startup noises are heard, go to step c below.
   b. If normal startup noises are not heard, turn the printer off, and then remove any installed accessories (for example, envelope feeders, paper feeders, or output accessories). Turn the printer on, and then listen for startup noises. If normal startup noises are heard, the problem might be with one of the accessories.
   c. Turn the printer off and then remove the power connector from the formatter. Turn the printer on, and then use a small pointed object (like a paper clip) to depress the engine test-page switch located on the rear or right side (depending on printer model) of the printer (near the formatter).
   NOTE: The test page can only use Tray 2 as the paper source, so make sure that paper is loaded in Tray 2.
   d. If the engine test page prints, the print engine is operating normally. Replace the formatter.
   NOTE: M631dn only: If the engine test page does not print, turn the printer off, remove the embedded MultiMedia Card (eMMC), and then try the engine test again. If the page prints, the problem might be the eMMC.
   e. If after replacing the formatter normal startup noises are still not heard, replace the DC controller.
   NOTE: If the error persists after replacing these assemblies, escalate the problem to the Global Business Unit (GBU).