CPU noise mistery

The CPU noise(high pitch hissing/buzzing/whining) especially when the CPU is in idle status bothered me. I tried the little software RMclock, It reduced the noise but did not eliminated it. I had to return 3 HP dv5t laptops because of this flaw. After a lot of research, I realized this problem happens more or less on almost all laptops of different brands using all kinds of CPUs. It's just a matter of level of tolerance. Some noises are not audible except you pressed your ear again the CPU area and listen very hard to tell it from the fan noise.

I got an HP dv7t recently and loved it, but this CPU noises bothers me again, what is different from previous situations is that the CPU noises does not become audible until you plug in any USB devices, once the USB device is unplugged the noise just become much less audible. Any explanation? Thanks in advance.

 

Hi,

I would guess that, when the "something" is plugged into the USB port, that it is drawing power from the laptop, and inside the laptop, in the power supply circuitry, there's probably some or a coil/inductor that "buzzes" when the power draw increases. I had that happen on a desktop that I built.

Have you tried plugging DIFFERENT USB devices in, and does it always make that sound with the DIFFERENT USB devices?

Maybe try plug the USB device into a "powered" USB hub, and see if it still makes the same noise?

Also, maybe try a different AC adapter.

Jim

 

Yes, I tried USB mouse, keyboard, flash drive, once a device is plugged in any of the 4 USB ports, there comes the noises. The same happens when the laptop is on battery, so changing the AD adapter might not help.

Do I have to open up the laptop and try to find the culprit and stabilize it with silicon or glue? or Is there other solution?

 

Hi,

All of those things you mentioned draw power from the USB port that they're connected to.

Any chance you can try to plug them in via a powered hub? That way, it'd be drawing power from the powered USB hub's power adapter, instead of from the laptop USB port.

I don't know if the problem is fixable. In the case I mentioned, with the desktop that I built, I had a really hard time even figuring out which component was "whistling". In the end, I just left it be, and lived with the whistling...

Sorry not to be more help ...

Jim

 

Hi, Jim

I did try to use a powered USB hub and it did not help. That's why I call this kind of situation a mystery.

Thank you anyway.

 

You're probably running into some capacitors buzzing when under load powering the USB devices. Unfortunately, it's common on all sorts of computers. My T61 graphics even buzz at times.

 

how to fix it? I searched the forum, It seems that this is the only way.
http://forum.notebookreview.com/showthread.php?t=389689