new antec chassis fan problem

dopemoney · May 8, 2016

so the fan came with 4-pin molex and 3-pin header connections. motherboard has 4-pin headers. when connecting the fan via mobo (sys_fan3), i get nothing, no spinning. when connect to psu of course i get full throttle. when connect fan to header and psu, fan is full throttle and BIOS will read fan speed properly. why wont fan run if only connected to mobo alone? fan headers are enabled in BIOS and set to .75pwm / C. which my understanding means that at minimum fans should spin up right after boot, no? currently, i have H55 connected to header cpu_fan, plus add'l Fractal fan (push/pull) on opposite side of radiator connected to psu, and front case fan connected to psu.

W-L · May 8, 2016

18 minutes ago, dopemoney said:

so the fan came with 4-pin molex and 3-pin header connections. motherboard has 4-pin headers. when connecting the fan via mobo (sys_fan3), i get nothing, no spinning. when connect to psu of course i get full throttle. when connect fan to header and psu, fan is full throttle and BIOS will read fan speed properly. why wont fan run if only connected to mobo alone? fan headers are enabled in BIOS and set to .75pwm / C. which my understanding means that at minimum fans should spin up right after boot, no? currently, i have H55 connected to header cpu_fan, plus add'l Fractal fan (push/pull) on opposite side of radiator connected to psu, and front case fan connected to psu.

Do you happen to have a link to the fan so we get an idea of now it's wired up.

LogicalDrm · May 9, 2016

You have set fan header to PWM mode. Set it to DC mode and try again.

dopemoney · May 9, 2016

http://www.newegg.com/Product/Product.aspx?Item=N82E16835209041

hey guys, thanks so much for responding. late last night i got it figured out...sort of. the new fan came with a splitter/adapter already attached (3-pin header and 4-pin molex). i noticed that the original connection for the fan is 3-pin header. so i removed the splitter and connected the fan straight to mobo and VIOLA! fan spun right up. plus, fan is being controlled and rpms are reading properly in BIOS. victory is mine! thanks again. could be that i do not have a full understanding of the purpose of the splitter/adapter though.