I'm doing my first home build and I'm having an issue getting it to boot up with my ASrock z68 motherboard. I have nothing but the PSU and motherboard hooked up, but when I try to start up the fans start up for about a second or two and then shut down, then pause for a second or two before trying to start up again and this would repeat until I turn it off. Here's the thing, I was told that the heatsink would come with a bit of stock thermal paste on it so I didn't apply any of my own, could this be causing it to overheat immediately and shut off? I've tried it with two different PSU's and the exact same problem happens. I removed the heatsink and there was definitely some silver paste on both the CPU and bottom of the heatsink, but I don't want to keep trying to boot it up and damage the CPU.
More about :installing heatsink thermal paste preventing startup
For Z68 you need PSU, MB with cpu and HSF and Memory installed for your computer to boot.
Based on your statement, you did not have the memory installed (need at least one stick)- no memory, no post.
The stock HSF, as you found out, had the coumpound on it. Since you removed the HSF you should clean it off and re-apply. recommend using artic silver 5. Use a pea size amount. I use a latex glove and spread that pea size lump evenly. Make sure the HSF is seated properly. On the back side you should see the 4 white nubs protruding.
Sorry, should have mentioned that the first time I tried this I had the whole thing put together: PSU, MB w/ cpu and HSF, memory sticks, harddrive, graphics card, and disc drive.. still got the same problem.
I'm going to pick up some thermal paste tomorrow and try again with the other parts hooked up. Hopefully I can at least get it to boot for long enough to make it to the BIOS screen.