LaserJet 4250n High Pitch Sound

[PM26]

My LaserJet 4250n makes a high-pitch sound when I first turn it on and when I start a print job. After a few seconds it goes away - until the next print job.

It does not sound like something mechanical. It's a steady high pitch tone. No grinding or other mechanical type sound. (Note: I am not saying for sure that it's not mechanical but to me it doesn't sound like mechanical.)

Printing quality is still good. Other than this sound, everything seems to be OK.

I put in a new toner cartridge. No change. Any clues or suggestions appreciated.

Peter

[Valsimot]

If you print like 10 pages is high pitch tone present all the time printer prints, and stops when the last page is printed? If yes that's probably a laser motor.

[Repairatrooper]

If you are using 3rd party cartridges it could be noisy drum units. Failing fuser bushings can also be problematic. If you go into trouble shooting an run component tests you might be able to narrow it down.

[PM26]

The tone is present when the printer is  warming up after power-on.  Once it's warmed up and ready to go the tone stops. 

The tone is also present for a few seconds when a print job starts.  After a few seconds it stops regardless of number of pages.

[PM26]

I have always used only original HP toner cartridges.

[Repairatrooper]

Any chance you have a UPS plugged into the same circuit as the printer. Printer may be drawing too much power and causing UPS to alarm about low voltage.

[PM26]

I do have a UPS on the same circuit but the high pitch sound is coming from the printer, not the UPS.

[Repairatrooper]

I suggested this because noises are sometimes hard to place, I had the same issue with a large police department where they had a printer plugged into a UPS which is a no-no.