Won't boot after reassembly

Hi all,

I am having some serious issues with my home built desktop pc. Earlier today I decided I was going to shut it off, gut it clean the the dust off of everything using air, I even removed the heat sink and processor wiped off the old heat sink compound blew out the heat sink applied new heat sink compound and re-attached the heat sink to the processor, so I get it all cleaned up and took the opportunity to re-route some of the power cables to clean it up (cable management). So I get it all put back together plug it in and it doesn't boot up it sounded like a hard disk kept spinning up and going to idle now it won't even do that. The power supply fan, case fan, and CPU fan all turn on for a couple of seconds then shut off, it just stays in that loop until I turn off the power switch on the power supply. I don't know what to do please help! Look below for system specs.

Intel Core 2 duo 3.3 GHZ processor
Gigabyte GA-B75M-D3H motherboard
Thermaltake TR2 600Watt power supply
PNY 120 Gig SSD
Seagate Barracuda 1 TB mechanical drive
LG optical drive
PNY DDR3 Ram 16 gigs
Windows 10 Home 64bit
Nvidia GeForce GT610 Graphics card
Sound Blaster Z sound card
Last edited:

Cycloid Torus

Posts: 4,845   +1,664
If you do not have the motherboard manual, you will want to download a copy from the manufacturer.

While a radical cleaning is usually a good thing, it is possible to miss something on the rebuild. When I do that, I take it down to basics. PSU plugged into motherboard with just one stick of RAM, keyboard, mouse, video subsystem and display, and my boot drive - leaving everything else 'off' for now. I will be happy with a clean POST (http://www.computerhope.com/issues/ch000607.htm) and even better would be a Windows load.

Once there is a good POST, the next steps are to add things one or two at a time and to check for good operation.

If no good POST, I remove everything from case and do a benchtop rebuild (