USB components flickering on and off


Jun 16, 2009
Hi guys,

I've noticed something strange lately when playing MKV files on my PC. USB components such as my external HDD, Keyboard and mouse start to flicker
on and off, and the video and sound is also very jittery. This has worked fine previously, maybe a month ago or so. So I'm wondering if HD videos
consume more power from the PSU than normal videos? If so, does this mean my PSU is struggling?

My PC specs are as follows:

Motherboard: Asus P5N-E SLI LGA775
RAM: Corsair VS2GBKIT667D2(1GX2)
DVD Drive: LG GSA-H44N
Graphics card: HIS HIS-4850-E3-IQT4 ATI HD4850 IceQ4 Turbo (Overclocked) PCI-E 2.0 512MB 256-bit GDDR3, 650/2000MHz
Monitor: Samsung 2243BW 22"
PSU: CoolerMaster RS460PCAR-A3 460W Extreme Power - ATX 12V v2.3, 120mm Fan
CPU: Intel E6420 CPU :Core 2 Duo 2.13GHZ @ 3GHZ
Mouse: Logitech G500
Keyboard: G110
HDD: 1TB Western Digital
Ext HDD: 1TB Western Digital MyBOOK
OS: Windows 7 Professional

Thanks in advance,



Jul 31, 2009
I wouldn't expect a power supply problem to manifest itself that way.
Perhaps try playing the files with a different media player, or stress the system to 100% by some other means and see if it's stable.
A bad PSU would probably crash or bluescreen the system.

Loss of power to USB devices would seem to indicate a motherboard issue...?