Is this sound/noise normal?

When my V2 M200 enters sleep mode it makes a weird looping sound, i’m afraid that it’s an awful symptom. But I can’t imagine of what.

A video link: https://www.dropbox.com/s/72k11bqzty3lofb/sleep.mov?dl=0

The only thing that occurs is that this is the same initial sound of the startup but in a loop. I don’t know either if it’s normal, but it was always like that (from April 2014).

https://www.dropbox.com/s/q0vq4509065rx2o/startup.MOV?dl=0

Mine does not make that sound.. V1

the same sound does my cpu cooler fan when it needs maintenance and cleaning and I see a lot of debris inside your printer. Take out the bottom plate of the printer and look if the fan in your mainboard works ok if not give it a clean and some lubrication.

Definitely not a good sound. It doesn't sound like a stepper (not impossible though) so I second Revitorio's suggestion to check all the fans. 

No, not the fans. Sure, there are a lot of debris but not inside fans, I'm not that insane, at lest not yet.

I fixed it. Was the PSU, a weird relay inside the PSU. What is funny is that this behavior was present since the beginning of the times, since I bought M200 in February 2014.

But as my first 3D printer, I thought it was normal... Only with sleep mode, present in the last firmware, this sound entered in loop, screaming that it isn't normal.

PSU replaced, noise disappeared.