2 weeks ago, my previous computer died. A black screen with a white blinking cursor was the only thing it still did. Curious about that, I opened the case and saw... leaking capacitors. According to Google searches about that, something went wrong with industrial espionage a few years ago. Nice, I had spied capacitors and a dead computer. Even more typical was the fact that my warranty had expired 2 years ago. And that all in a week I planned to develop on my blog and some other private projects. The best cure to quicly get to work: a new computer.
So I went to my local computer store and ordered some new parts (motherboard, CPU, memory and a new graphics card). One week later, everithing arrived and I screwed everything in my computer case. Everything worked, I installed Windows and all other software, and decided to have a look at the internal temperatures... 71 degrees Celcius!!! Good to know that a Pentium D 915 gets hot when you have not enough ventilation in your case...
After buying 5 new coolers (2 for HD's, one front case fan, one rear case fan and a blower on the bottom) and installing them, my new PC adventure was not over... It didn't boot anymore!
Weird... Installing fans using just a bit of current influenced my computer. Anyway, I decided to take out all parts and re-install them, and see when it would't boot anymore. That way, I would know which part was defect. Very nice: I only kept my motherboard, cpu, memory and graphics card, plus the CDROM drives. No booting...
I tried plugging in the power connectors in my HD's one by one. DON'T TRY THIS AT HOME! I did, and one hard drive caught fire... Quickly pulling off the current and pulling out the HD (luckily, I didn't screw anything into place yet), didn't prevent the hard drive from dying too. Byebye, 120 GB's of storage...
3 hours later, I found out the ATA cable to my CDROM drive had died too. After replacing that, my computer worked again. Temperatures are better now, too. Everything except the CPU is below 30 degrees.
Conclusion: if you are trouble-shooting your hardware, make sure all cables work correctly...