Hp clj3000

[MLS5262]

I have a customer that is concerned about an electrical buzzing noise coming from their Hp clj3000dtn. Its not extremely loud, but in her quiet office, it is annoying. When I removed the top cover I can hear that it sounds like it is coming from the low voltage power supply, from the corner where the power switch and plug are located. When the printer is idle, but not in sleep mode, it will buzz for about one second then off for about three, and do this repeatedly until it goes into sleep mode.

The customer claims that the unit did not originally did not do this, but has only started recently.

I tried replacing the low voltage power supply, but it does the same thing. I am trying to determine if its supposed to make this noise and what process is causing it do it. Maybe my hearing is off and I'm not hearing where the noise is coming from accurately.

Any thoughts?
Any questions, please ask.

thanks

[MichaelTech]

Possibly the fuser, since it's up there too. If a duplex model, the duplex re-drive may be going bad. It is attatched to the top cover. Check the Duplex PCB. A relay in the L/V could be it, if you changed it, doubtful.

[MLS5262]

thanks for the reply

I will double check the location of the noise to see if it is closer to the fuser. I ran the machine with the top cover completely removed and off the unit and it still does it, also with it connected.

I did find the following article on hp's site:

HP LaserJet 1000, 1200, 2800, 3000, 3200 and 3300 Series Products - Periodic Noise
ISSUE:
The HP LaserJet 1000, 1200, 2800, 3000, 3200, and 3300 series products periodically make a noise when sitting idle.
CAUSE:
After printing, the product continues to heat the fuser for a few milliseconds and then turns off. In addition, the fan will run for approximately 25 to 30 seconds after the print job is finished. After approximately 3 minutes, when the fuser has cooled off, the printer will momentarily engage the drive to rotate the surface of the film about 0.064 inches (3 to 3.5 mm). The process of heating, cooling, and rotation allows for cleaning off of the excess toner from the rollers. This is part of the post-print cleaning process that is normal for the printer and should not cause alarm.

I'm not sure if it is the same noise that they are talking about.