Question about Biostar K8M800-M7A Motherboard

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Power supply and CPU fan problem

I am installing a new motherboard and when I plug in the power cord the power supply and CPU fan come on without me pressing the "On" What have I done wrong?

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Re: Power supply and CPU fan problem - Biostar K8M800-M7A Motherboard Motherboards

I did anyting. But, problem is same.

Posted on Dec 25, 2007

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Re: Power supply and CPU fan problem

You dint mention the mother board u are using in some motherboards jumber setting can power up the system check the jumber setting in the mother board near ur front pannel pins in ur motherboard

Posted on Nov 30, 2007

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Turn on problems

check power supply then make sure that the main power cable is in plus the 4 pin and 24 pin are the main ones first then hard driver then cd or dvd rom cpu plug as well on board it says cpu fan try new power cord as well

Dec 25, 2013 | Motherboards

1 Answer

Please clear cmos if system no display after overclocking

Click the following picture to enlarge:

CPU Overheated
If the system shutdown automatically after power on system for seconds, that means the CPU protection function has been activated. When the CPU is over heated, the motherboard will shutdown automatically to avoid a damage of the CPU, and the system may not power on again.

In this case, please double check:
1. The CPU cooler surface is placed evenly with the CPU surface.
2. CPU fan is rotated normally.
3. CPU fan speed is fulfilling with the CPU speed.

After confirmed, please follow steps below to relief the CPU protection function.
1. Remove the power cord from power supply for seconds.
2. Wait for seconds.
3. Plug in the power cord and boot up the system.

Or you can:
1. Clear the CMOS data.
2. Wait for seconds.
3. Power on the system again.

If after clearing the CMOS you still have no display, you may have damaged your motherboard, CPU, or RAM. If you need further assistance with this Motherboard, let me know.

Mar 25, 2011 | Biostar G31-M7 TE Motherboard

1 Answer

My custom built computer has a the m7vig400 installed and i can't formatt my new harddrive because the fan on top of my processor will not come on why ? it came on with a 16 head hard drive how do i...

First, make sure you plug the power from the fan back into the motherboard & try it again. Did you do anything else besides just pulling out your old hard drive & putting the new one in? The CPU fan is completely independent of the CPU fan. You can start up you system without ANY hard drives & the CPU fan will come on if it's plugged in & the power supply is working etc. If you make sure the fan is plugged in correctly & the fan still doesn't come on, I suggest you temporarily put your old hard drive back in & firing things up. I'm sure you will find that the fan still doesn't work.

All that said, if the CPU fan isn't working (& everything else is), then it's a bad fan or motherboard. It's not necessarily a bad motherboard. Sometimes there are jumpers that control that sort of thing. I'm not sure exactly what that motherboard does. I have had this exact motherboard for years & as long as the fan is plugged in (& the power supply is working), when you start things up, the fan comes on.

One last thought, try flipping the power supply switch in the back to reset the power supply before you press the button in the front. Good luck...

Jan 07, 2011 | Biostar M7VIG-400 (M7VIG 400-COMBO4)...

1 Answer

My CPU Fan and Power Fan is spinning just a moment!! firstly , i check RAM, CPU Fan and CPU and then Power Supply... but all of parts are good !!! i think , this problem is possible because of my...

It's not the RAM.
It's not the CPU.
It's not the power-supply.
Turn the computer off.
Disconnect the power-cord.
Disconnect the power/data cables from the 3.5" diskette drive, the disk-drive, and the CD-ROM drive.
Disconnect the mouse.
Disconnect any printer.
Remove any USB devices.
Reconnect the power-cord.
Turn the computer on.

If you still have the problem, then it MUST be the motherboard.

Sep 27, 2010 | ASUS P5G41M LE Motherboard

1 Answer


Good day sir, let try to test first the power supply, Unplug the power cord, remove the 20 pin (24 pin for the late model) molex power connector from the motherboard, plug in the power cord, get a 2 to 4 inch jumper wire, short the green wire with any of the red or black wire on the molex 20 pin power plug, the result maybe the following:
  1. you will see the power supply fan turn. you power supply is in good order. replug the power supply, and test again.
  2. you will see the fan turn for a few second then stops. you power supply is selective, and may require a different type of motherboard. Get a new one.
  3. you wont see the fan turn at all. get a new one.
If in case you are with #1. uinplug the power cord and remove all the expansion cards, data cables from the hard disk and cd drives. we are trying to isolate the problem. make sure that the only connected cables on the motherboard are as follows:
  1. 20 pin power cable.
  2. 4 pin 12 volt power cable (if applicable)
  3. speaker
  4. power switch
  5. power led
Test the pc once more. plug in the PC. If still the board wont power on. problem with your motherboard. Note:make sure your RAM is good. Hope this helps.

Aug 26, 2009 | Biostar I865GV-M4 (MB865GVM4) Motherboard

1 Answer

Fans run without turning on front switches

Hi Gene,

If you've installed the cpu and hooked the fan to the power supply plug, which is just left of the cpu mount, then the board if connected to the power supply cables, it should start up. Regardless of the front switches. However, you probably don't want to start plugging in the power cord until you have all of your components in place and ready to close up the case. First you can create a shock by just touching the board and that can damage the board. (I speak from my own experience :-( .

But once you get the power switch plugged into the board that should take over turning the rear power supply on and off (Including the cpu fan)

Good Luck and don't forget to leave a rating, based on my solution.

Thanks Mark

Apr 16, 2009 | Intel D865PERL Motherboard

1 Answer

System will not start up. Cpu fan spins once, then nothing.

It is more than likely that when your old power supply died a death, it damaged some components on the motherboard. Replace the Motherboard and chip, and you should be back in business. You can pick up some good value bundles to save money on buying the parts seperately. The power supply working again after turning off and on, is because there is a little trip in the power supply that triggers when it detects a fault. Powering down resets that trip allowing it to try and work again.


2 Answers

Asrock P4i65G Motherboard

If the CPU is dead the problems can be
  1. no power
  2. no fans etc or
  3. power, no beeps (errors)
If the Ram is not compatible it would be constant beeping.

With the board in, and power supply 20pin + 4pin Pent 4 power attached,(#2 and #7 of motherboard layout) remove power cord from power supply.
CLRCMOS0 allows you to clear the data in CMOS. The data in CMOS includes
system setup information such as system password, date, time, and system
setup parameters. To clear and reset the system parameters to default setup,
please turn off the computer and unplug the power cord from the power
supply. After waiting for 15 seconds, use a jumper cap to short 2 pins on
CLRCMOS0 for 5 seconds. Remove the jumper. Remove heatsink and fan from CPU. disconnect cpu and reseat it. Re-install heatsink and fan. Plug in the power cord. Try to boot up. If it still does not boot and (no power, no fans etc.) problem would then be cpu is fried.

Jun 02, 2008 | Motherboards

1 Answer

Compaq Presario 4400us

Either the new power supply you purchased is not functioning correctly. But, assuming it is now that you are getting some form of power to your PC, it is very likely the motherboard. Whatever fried your old power supply (or it could have just been the power supply itself) most likely fried your motherboard in the process. Probably not the CPU since the MB can't even post.

Jun 21, 2007 | Compaq (388746-001)...

1 Answer

No respons at all !

I think your power supply cables is not able to start your B-board if your power supply is working properly then check mother board jack where you insert your power supply plug in M-board. Then you have to change or repair that jack where you insert power supply wire in M-board. With best regards M. Khalid Shaikh from Pakistan Mobile: +92-332-2631983

Sep 19, 2006 | Intel Desktop Board D845BGSE Motherboard

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