Yesterday a friend asked to look at his old computer. He told that computer crashes randomly with Blue Screen of death (BSOD). He suspected to be HDD problem due to bad sectors or so. He also wanted to save his pictures at least if nothing else can be done to make it work. Well I took PC for inspection.
First of all I tried to save pictures – copy them to flash memory. Started up computer and what you know – Antivirus software expired long ago, virus is thriving. Found out that it is worm:Win32/Brontok@mm. From its description I found that:
Win32/Brontok is a family of mass-mailing e-mail worms. The worm spreads by sending a copy of itself as an e-mail attachment to e-mail addresses that it gathers from files on the infected computer. It can also copy itself to USB and pen drives. Win32/Brontok can disable antivirus and security software, immediately terminate certain applications, and cause Windows to restart immediately when certain applications run. The worm may also conduct denial of service (DoS) attacks against certain Web sites.
OK problem solved I thought. Of course virus took over whole system and I couldn’t install any antivirus. I didn’t want to dig deeper in to cleaning it. Wanted just copy about couple gigs of photos and format disc for new installation. I took blank flash memory and started copying. And want you know – computer started throwing BSOD screens. After restart I could only copy few files before it threw another. OK I thought – virus done quite damage, let’s load mini windows XP from Hiren’s boot CD. Maybe here I will have enough time to copy files without BSODS. There was the same – after few files were copied I was faced with BSOD. Every time different error message, so no point of looking for solutions on the web. The only thing that was in mind – hardware problem. During several restarts I managed to copy all files with viruses to flash drive. Virus created several .exe files on flash. Deleted them and run Antivirus scan from another PC. Virus was gone from flash and photos were saved.
Catching hardware problem
Time to catch hardware problem. From same Hiren’s boot CD I started memtest86 program. This is a number one RAM test utility that runs several thorough tests on RAM modules. And what you know – it found one bit where errors came on every test. So I thought – problem solved! Luckily I had one smaller DDR2 module lying around (1G instead of 2G) that had no errors. Replaced RAM, formatted disc and started installing new windows. And what you know – just before windows started copying its file – BSOD. It cannot be I thought and started over – again BSOD with different errors. Maybe there are hard drive problems – run surface test for some time. No errors appeared. So HDD seemed in tact. Another thought that came to mind – maybe bad install DVD. Took Ubuntu disc and tried to load it – nop it even didn’t load itself from DVD.
So we came almost nowhere. Checked CPU temperature and core voltage in bios. It seemed alright, maybe a little to low by couple hundreds milivolts. Nothing very suspicious. But just in case I decided to clean CPU cooler from dust. And what you know. Look what’s hiding:
It seems that two capacitors near CPU radiator has been blown.
This is a problem I thought and disassembled computer motherboard and replaced both caps with new.
I left one in the middle to be, because I had only two that matched size and capacity for replacement. Other at least visually looked OK. Put computer together and all problems were gone.
It was quite fun that took all day with breaks. I am not some professional PC hardware engineer, but with intuition and some engineering knowledge any problem can be solved. The difference is how much time it will take. Hope you find this somewhat interesting and useful. Maybe you had similar problems. Please share in comments or head to forum.