I looked around a bit in the forum at first, before posting, but I thought maybe now I should do so.
About the problem: I have a 3 year old PC, and two days ago it started to not pass POST (as I think it is called) i.e. it seems to boot for one second: I can hear the fans, and it shuts down afterwards.
The first time that happened, I opened the case and removed A LOT of dust.
I tried booting, and voila! it worked! (yay)
The day afterwards, it started with the shut down again.
I tried checking the different power supplies: disconnected the HD, and it worked. So I changed the power connector to the HD, and it worked! (yay!)
To check if it was the power connector to the HD, I shut down the pc after some hours, went for a walk and came back again. And again, it only started for one second, and then it shut down. I tried disconnecting everything: HD, DVD drive, Video card. Only the MOBO was connected to power through those two connectors which I do not know the name. (that big one, and that little one with only four pins.) It didn't work. I tried disconnecting the smallest one from the MOBO and tried again. It started up. I shut off everything quickly.
So, after reading around in the internets, I thought maybe it was the PSU. So I went to a store, told them my story, showed them my PSU. They passed it through a tester, and told me it looked fine. But they also told me, that there was nothing connected to the PSU at the time, so it didn't have any strain, so it could malfunction anyway when i connected everything. That they would actually try out a different PSU. And if the PSU isn't the problem, it will most probably be the MOBO. So I took a new PSU back home, fingers crossed, and tried it out. It didn't work.
I think now it has to be the MOBO. What do you think? How should I go about finding a replacement MOBO? mine is a GF7050V-M7 SE.
Do you need any more information?
Thanks in advance!