PC doesn't start

luggyx · Post by **luggyx** » 17 Aug 2009, 02:32

Yesterday I got one pc box in my hands. This pc doesn't work properly. The main problem is that pc stars just every 3-5 time then I turn on power when press on button.When fans moves little and stops after making some noise.After several time switching power on and off pc starts but screen shows no signal . I was thinking about short-circuit in one or another pc component so I switched them all of power but motherboard doesn't start normally . So i wanna ask you guys its a motherboard broken (witch I think is) and I should buy new one or its another problem ? What do you think

Thanks for any help

p.s feels good to have backups

skip · Post by **skip** » 17 Aug 2009, 04:32

Do you happen to have any spare computer parts to swap it and test which one has the problem? how many beeps did you hear?

http://www.computerhope.com/beep.htm

check the capacitors if they are bloated or feel the heat of the capacitors by touching it gently; if it is, then its defective. Also check the PSU if its still supplying the right amount of voltage to the mobo.

Post by **floodhound2** » 17 Aug 2009, 06:40

I just fixed a computer that had the same type of problems. What fixed it was to unplug the main power connector on the motherboard and reconnect it.

You might want to disconnect all the parts and reconnect them, reboot checking for a good post.

luggyx · Post by **luggyx** » 20 Aug 2009, 09:20

Thanks but It didn't helped

all parts are working normally but pc doesn't :/ Any ideas ?

Post by **DNR** » 20 Aug 2009, 10:31

Ok, you said you swapped all the external devices and it still failed to boot. If the PSU is ok, then we are left with the mobo.

You can remove the mobo from the box and examine both sides of it. You are looking for fried components, board tracings that burned out, signs of overheat (the coating on the board will melt away or discolor). Make sure that you handle it by the outside edges, not any metal contact strips, and that you ground yourself.

There are various ways to ground yourself, my professional taught tactic was to leave the PC box plugged in (notice the green wire attached to the frame of the box - thats the ground wire to the plug) the wall outlet provides ground and as long as you do not open the PSU you will not get a AC shock and the DC voltage is minimal. As long as you touch the metal frame you are grounded through the outlet.

ESD would have to reach about 3,000 volt for you to notice it, and it can take millivolts (smaller amounts) to kill a electronic device. The painful ESD you can feel is about 30,000 volts.

DNR

DrVirus · Post by **DrVirus** » 20 Aug 2009, 12:15

Did you check the power supply ?? I mean by the sound of it, "the fans moves a little then stops after some noise" it could be the smps. Can't be sure. Did you swap test it ?

luggyx · Post by **luggyx** » 24 Aug 2009, 10:29

It was power supply and motherboard thanks for help guys

Post by **DNR** » 24 Aug 2009, 15:10

Man, its too bad shipping is expensive cuz I got some decent boxes that work. Save the other stuff for parts and hang the mobo on the wall - its cool to look at.

DNR