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PSU fan and CPU fan start and stop anytime i press power button

7K views 13 replies 6 participants last post by  accat13 
#1 ·
I just bought a new ASUS P5VDC-X motherboard motherboard, a pentium dual-core E2160 processor
a 256 PCI Xpress card,160 gig hard disk,DVD rW.......I fixed everything up....but when I press the power button...the CPU fan and the PSU fan come on for 1 second and then go off....nothing shows on screen.I really need help...coz i worked frikin hard to buy this PC....
 
#4 ·
I don't think this could be the case because the CPU fan works independently of the CPU. Why not take out the CPU and power-up the motherboard again (don't install the heatsink and fan, just plug the fan's power cord). I had a somewhat same issue when I was working on a motherboard out of its case and it was sitting on some conductive material in certain spots, so I think it short circuit something. This will most likely not be the case with you, however.

Does the PSU turn off completely or just its fan? If the PSU goes off completely then maybe I should reconsider the problem being some short circuit somewhere, because what activates the PSU and also shuts it off (in some cases) is a "jump" (as in "jumper") in 2 pins on the motherboard. I would take the motherboard out, plug nothing but the PSU's power cord and then fire it up by using a (flathead) screwdriver to connect the corresponding pins. If the problem persists, then it's gotta be either of the two. If not, well, you've made a good start at finding it.
 
#5 ·
thanks all of you.BOOK, i will try to get that done too..........the power supply works fine....only the fan goes off....i switched power supplies..the same thing happened.on the motherboard manual...it says "the board supports dual core CPU's with 65nm,hyper threading technology.....and the E2160 has all that..... one more thing....the board has this 24 EATX connector,am using a 20 pin ATX connector,any effect?thanks.
 
#8 ·
accat13 is correct. If the board does not support the E2160 the BIOS cannot read the processor microcode and the machine will not boot.
Booting has *nothing* to do with powering the CPU fan OR the PSU fan. In normal circumstances, those components draw power even if there is NO CPU or GPU or whatever other component, except the motherboard of course. So all I can say about that is turn on your PC with only the motherboard and the PSU, then see if the problem persists.

The power connector would be a reasonable cause of the issue if it does not match that of the motherboard's, although those extra 4 pins don't provide any extra (different) voltage that the normal 20pin (and the 12Volt 4pin).
 
#9 ·
Most likely this is NOT the case but...I had the same thing happen when I built my first computer a few years ago. It turned out that I had not connected the CPU power plug to the motherboard.
 
#10 ·
Booting has *nothing* to do with powering the CPU fan OR the PSU fan. In normal circumstances, those components draw power even if there is NO CPU or GPU or whatever other component, except the motherboard of course. So all I can say about that is turn on your PC with only the motherboard and the PSU, then see if the problem persists.
What he describes, i.e. the processor fan and the power supply fan coming on momentarily and then turning off is a common problem with a new installation of a socket 775 processor. The main cause is the cooler heatsink not contacting the processor heatspreader under pressure. A socket 775 processor has to have a load of at least 17 (f/lb) of pressure or the machine will not boot, and you will get the described symptoms.

A BIOS that is not reading the processor microcode will produce EXACTLY the same symptoms.
 
#11 ·
one more thing....the board has this 24 EATX connector,am using a 20 pin ATX connector,any effect?thanks.
I would say yes from the manual it says it will not boot with a 20 pin....I have a couple of p5rd1-v's that will boot but only with the onboard video.Your case is totally separate you need the 24 pin psu to boot ...I'm not a big fan of the adapters 20 to 24 pin I would suggest reading the manual and getting a good 24 pin psu (the heart of the pc)..as well as ram that is on the manufacturers list.Good Luck :)
 
#13 ·
As accat13 states the 20 pin mainboard connector will also be a problem. ATX spec 2.01 section 1.2.3 adopted the 24 pin mainboard connector which added pins 11, 12, 23 and 24 specifically to supply power to the PCIe buss.

If the board has onboard video the machine should boot with the PCIe card removed, assuming everything else is correct. The problem with trying to use a non supported processor is that BIOS cannot read the processor microcode, therefore it cannot instruct the VRM as to how much voltage to supply to vCore.

If you check the board manufacturers website there MAY be a BIOS update that will add support for the E2160 processor. If you search the archives here at TSG you will find several instances where people initially purchased the incorrect processor, however it was later supported by their board with a BIOS update. In those cases it was necessary that the builder purchase a processor supported by the original board BIOS, install it, flash the BIOS to the latest update, remove that processor, then install the previous non supported processor. If there is a BIOS update that will support that processor, another option is to purchase a BIOS chip with the latest update, and replace the BIOS chip to support the processor.
 
#14 ·
I really hate to say this but you may be going at this the wrong way....The ASUS P5VDC-X is a *******ized board a little bit of the old a little bit of the new...ddr,dd2 pci express x16,agp 8x ,see what I mean...You may be better off explaining to us what parts of your old system(specs) you trying to save if any.I would think it would be better to keep the cpu and ditch the board.The newer cpu's give a great bang for the buck plus cooling is not a problem.The older ones have a tendency to be more expensive not as efficient and run hotter also supply becomes an issue.
 
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