random PC freezing, sound buzzing, restarts prob.

Hi there, topic says what is my PC doing to me. Its randomly restarting or freezing with black screen and i hear buzzing sound from my repros. Everything has started when they put ati 2600 HD pro in. Ive bought a newer 3850 but the problem has carried on.

What Ive tryed so far?
I tryed to switch RAM module, seems to not have effect, I got new PSU, Eurocase ( ya i know, poor student ) 550W and got that new ati. Ive installed various drivers for graphic card or sound card AC97.
Also I underclocked my GPU , nothing happened at all, temperature is good I think, around 70 C with 98% gpu activity, according to catalyst control centre.

Every problem capable of sensoring (everest, sandra, speedfan,..) told me that my +12V is about 0,12V (sometimes 0,88V) but I think thats problem of my mobo's sensor, because it cant be that low to run it. Bios says that voltage is OK.

My PC:

Intel C2D 4300@1,8G
2Gb DDR SDRAM 633Hi there, topic says what is my PC doing to me. Its randomly restarting or freezing with black screen and i hear buzzing sound from my repros. Everything has started when they put ati 2600 HD pro in. Ive bought a newer 3850 but the problem has carried on.

What Ive tryed so far?
I tryed to switch RAM module, seems to not have effect, I got new PSU, Eurocase ( ya i know, poor student ) 550W and got that new ati. Ive installed various drivers for graphic card or sound card AC97.
Also I underclocked my GPU , nothing happened at all, temperature is good I think, around 70 C with 98% gpu activity, according to catalyst control centre.

Every problem capable of sensoring (everest, sandra, speedfan,..) told me that my +12V is about 0,12V (sometimes 0,88V) but I think thats problem of my mobo's sensor, because it cant be that low to run it. Bios says that voltage is OK.

My PC:

Intel C2D 4300@1,8G
2Gb DDR SDRAM 633
WD 150Gigs SATAII
Ati 3850 HD 256Mb
Ac97 7.1 audio
N650SLI-DS4 mobo
550W Eurocase PSU

Any help would be really appreacited.

Best regards, Maddox
WD 150Gigs SATAII
Ati 3850 HD 256Mb
Ac97 7.1 audio
N650SLI-DS4 mobo
550W Eurocase PSU

Any help would be really appreacited.

Best regards, Maddox

So you are suggesting that first of I should try to unplug my dvd-rom? I just have one, or I can try and just plug that card alone onto one sub-circuit. I didnt mention that sometimes this only happens when my PC stresses up, for example game lag or short freeze

well, it looks like its gone, or maybe Im just lucky, it was very randomish when pc froze up. ill let know if that black box will get on my nerves again thanks Yuka

Reporting : Even after unplugging of dvd-rom problem still persists, I really think its somehow related to my AC97 audio, maybe its in conflict with that 3850 card, but im unsure why. Ive heard that this card has its own audio integrated inside, since its HD. I think this because my pc froze up during some web stream.. and that shouldnt take much of video cards juice

I did as you said, removed every ATI driver, used that cleaning thingy to get rid of the rest.. I tagged every driver with word "ATI" and cleaned it. Then I run my favorite PC "freezer" WoW and it crashed within a minute.

However, earlier this day, I disabled the audio in bios, tryed silence mode for couple of hours and it didnt crash at all..hmm