Cpu fan not working but only when ram is in

[Pc-man88]

hello,
i have saber tooth z77 motherboard with a ivy bridge i5 and kingston hyper x ram. the fan runs when the ram is out of my computer, but once i remove it the fan does not spin fully, it only gives a slow quarter turn

 

[Novuake]

How is this a problem? You can not run a PC without RAM. The board will just switch of without RAM.

 

[Pc-man88]

whenthe ram is not it nothing comes up, i have never ran the computer before

 

[PanicMaster85]

put the fan into the sys_fan slot

This should make the fan go 100% always(which is better than 0% right )

 

[Pc-man88]

i did plug the fan into the system fan slot, it give a slight quarter turn when it does work

 

[PanicMaster85]

have you tried the other Ram Busses?

 

[Pc-man88]

yea i have tried with just one stick, then two sticks in every combination. if ram is in the first two ram busses the fan spins but no video comes up. it just has a blank screen and no prompt

 

[photonboy]

Please confirm:

1. You are using the CPU_FAN slot for the CPU fan.

2. You are ONLY putting your RAM in the slots your motherboard designates.

3. your motherboard BIOS is up to date (flash if not)

*I think some of the confusion is your initial wording.

**Also, be aware that some FAN PROFILES might have your fan spinning SLOWLY in idle mode as that's sufficient to cool the CPU.

In other words, there might be nothing wrong.

 

[Pc-man88]

well i have seen the fan moving at full rpm, but when the computer starts and boot the fan basicly does not move, i have never used the computer b4 i have just built it

 

[PanicMaster85]

huh so then just on start up the fan does not move but when the computer is on you can see it going full rpm?

 

[womble]

With no RAM modules in I expect it isn't posting so will just run the fans at a full power state. What do you have the fans set to in the BIOS? there is a monitoring section and you should be able to set a minimum speed etc.

 

[Pc-man88]

even when i go into the fan monitoring section the fan keeps just giving one slow turn every few seconds

 

[PanicMaster85]

huh do you have any other fans you can test maybe with a 120mm case fan? also does it spin just fine after start up?