# My PC won't turn on but the fans work



## rj2.upd (Apr 26, 2011)

Hello.

My problem is started after I bought a new power supply. First thing i noticed was the Power LED and HDD LED wont light up, I tried changing the orientation of the chassis power LED cables of both HDD and power to no avail. (I did not transfer them to other pins, just flipped them) The monitor doesn't display anything, its power LED just blinks. The fans of both the CPU and PSU work.

Specs

Pentium 4
2x 256MB DDR1 PC400
ASUS p5v800-mx

Any help would be appreciated. Thanks.


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## rj2.upd (Apr 26, 2011)

The power supply is Intel AMD P4-600W.


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## dai (Jul 2, 2004)

check your main power plug is in all the way

check the p4 aux plug is plugged into the m/board

what do the fans do when you try to start


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## rj2.upd (Apr 26, 2011)

Hello there.

Thanks for your reply. My main plug is in all the way. I do not understand what p4 aux plug is, I am double checking the motherboard manual so please give me the full name.

When i push the main switch, both the cpu fan and psu fan turn on, they spin if that is what you mean. Please bear with me as I am not that familiar with this.

I will wait for further instructions. Thanks.


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## dai (Jul 2, 2004)

http://www.techsupportforum.com/forums/attachment.php?attachmentid=43990&d=1235344680

your plug socket is located near the center of the m/b and the plug has 2 black and 2 yellow wires


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## rj2.upd (Apr 26, 2011)

Hello. Thank you for your reply.

I checked and they are connected.


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## dai (Jul 2, 2004)

see if you can borrow another psu to try in it

it's only agp so something with 18A or more on the 12v line should be ok to check with


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## rj2.upd (Apr 26, 2011)

i have a working psu that i could use but it is being use by another computer. Do i have to remove the psu?. Also, i need to know what connections are essential if i only need to check.

if you could give me a step by step instruction, it would be very helpful.

thanks.


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## dai (Jul 2, 2004)

if the cables are long enough you can unplug the the main and aux cables and connect them across to the computer

this should give you post,the single bios beep and the bios screen

if they are not long enough you will have to pull the psu out you don't have to fit it to the case can have it sitting outside to run the check


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## rj2.upd (Apr 26, 2011)

Hello.

OK, i believe they are long enough. Kindly talk me through on how i should connect the wires.

Thanks.


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## dai (Jul 2, 2004)

you just unplug the the 2 power plugs to the motherboard and then plug them into the other m/board


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## rj2.upd (Apr 26, 2011)

Hi again.

I did what you told me. Now the fans don't work and the green LED that lights up when the pc is plugged doesnt light at all.

What should I do next?

THanks.


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## dai (Jul 2, 2004)

it would seem the psu is not up to the system

reset the cmos

with the new psu in unplug power from the drives and see if it posts


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## rj2.upd (Apr 26, 2011)

Hi again.

I reset the cmos via removing the 3v battery for 30 seconds. I disconnected the power supply of the HDD. The same thing happens, fans on, HDD LED off but now the power LED lights up. Did not have a display on the monitor though.

How would i know if "it posts".

Thanks

i just noticed something on my motherboard. the lone capacitor near the words USBPW56 and USBPW78 is larger than the others, it appears to be bulging.


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## dai (Jul 2, 2004)

then that is your problem any swelling or leaking means it has gone

Badcaps.net - How To Identify


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