I took it apart and found the fan was the cause.
Xbox one psu fan noise fix.
Clearing out the dust made no difference.
However gamers do have one common complaint with the console the xbox fan.
Put the psu away from sources of direct heat like radiator oven furnace amplifier or heat register.
There s a couple of steps that you can do to fix a bad xbox one psu.
My xbox one ac adapter started buzzing one day.
Check the link below kenny tells how he installed a replacement fan 10x10 fan from mouser bfb0512hha c with good results.
My sons xbox kept making this weird noise while he was playing it was driving me mad someone said it was dust on the fan so while he was out i cleaned it i got the hoover and hoovered any where i could see that there was and vent leading inside the xbox and it worked for a short while so now every time i hoover up i go over the xbox and since i ve been doing that no whistling thank god.