cpu fan problem, computer failing to load

hi guys, just built a new system here and running into a few problems

its a uBTX factor case and motherboard, and i believe my problem is either with the 4 pin connector for the thermal module or with its connection on the motherboard itself, as the computer boots fine when i plug the thermal module into a 3 pin fan connector but nothing comes up on the screen when i plug it into the 4 pin connector

problem is that i need to use the 4 pin to regulate fan speed as its way too loud otherwise

any help would be greatly appreciated

thanks

it does work when i plug it into a chassis fan but not when i plug it into the cpu fan, which is where it should go - its just not ideal having it plugged into the wrong plug as like i said it wont regulate the fan speed

it did work once when i plugged it in there but i moved the machine and it didnt work again

when i plug the 4 pin cable from the thermal module into the 4 pin connection, ie the cpu fan connection, the computer makes noises as though it were working but i get no video output on the monitor, on one occasion when i had the thermal module hooked up to the 4 pin cpu fan connection as described it did function normally, the fan speed was slower (as desired) and the computer booted just fine, but as soon as i switched it off and moved the machine to its location the computer wouldnt boot anymore

the only way i can get it working reasonably is to hook the thermal module up to a 3 pin chassis fan connection, when i do this everything is ok and im getting a cpu temp of around 30-32 degrees C

yeah i figure its either got to be a problem with the fans connector or the place on the motherboard where it connects to, but i have no similar fan to try on it

i really cant use it with the fan at 100% as its loud as hell and the reason i built this is for audio applications haha its doing my head in