This is both frustrating and interesting. Xerox support seems unhelpful just saying stop it from going into standby! I have a recently bought June 2020 Xerox-6515DNI which I am otherwise very pleased with. I am sure the noise is coming from the switched mode power supply that is dropping into the audio spectrum when it is in a low power (and otherwise quiet) state. I think this is a well known phenomenon with these power supplies under low load.
For interest. Can I ask all those who comment on discomfort with this issue in future, to state their AGE (not DoB) as high pitched loss is usual with age. I am 62 and have good hearing BUT it was my 7 year old grandson who complained about the noise. I can hear it if I try. It seems to come mostly from the perforated window front bottom left of the printer. I wonder if some acoustic wadding over there would help? There may be one component e.g. an inductor coil that could be selectively damplened e.g. with a blob of glue, that might make all the difference.
Has anyone tried that? A photo would really help. I have not disassembled mine yet.
As reported earlier this issue was escalated and here is the link to the response to the noise issue posted (May 21, 2020). Noise Article
Has this been resloved as I am having the same noise issues?
Noticed that the noise tops when using touchscreen but back again after
Very frustrating when idle.
Unable to have it switched on - must be a fault!
We are currently researching this issue, could you please let us know which system software or firmware version you have loaded on your machine?
I have returned the Xerox to my dealer who was kind enough to offer a full refund. I exchanged the Xerox for a comparable HP model, no noise whatsoever. Specs-wise I would have prefered the Xerox, but since they are not acknowledging the issue - which to my ears is a severe defect that would also stand out in a larger office - I had no choice.
Having done some reading I found out that most countries do not have regulations on noise production above 8 kHz, so I am guessing that Xerox does not test for this issue, but is sounds like a product-related defect to me.
My printer arrived just today and is also making the noice. It's really annying and my setup is such that the printer sits right next to me on the table.
A service engineer from Xerox came by today, but was unable to hear the noise (ability to hear high frequency noises is heavily age-dependent) and even though I was able to show the clear peaks at 12.3-12.5 kHz he was reluctant to start swapping out parts at random. Next step is to contact the dealer and see if I can either get a replacement unit (if that does not have the same issue) or a refund.
I just got my unit in today and have exactly the same issue: a high-pitched whine 12.4-12.5 kHz that starts as soon as the printer enters sleep mode. I have attached a screenshot of a spectrum analysis tool that I run on my phone. Did you get this resolved through support (I am having a hard time registering for Xerox support)?