MY pc wont turn on!! HELP!!!

[christophicus]

HI first off , i know nearly nothing about capacitors, but i do know a bit about pc's.

OK so heres the deal. I just bought a pc(without HDD) Of a guy in my town.

The thing is ,it wont start up. The guy I baught it off said it wouldnt start up when here tried but said it was something to do with the power button not being wired up right.

I now know that the power butten does indeed funtion correctly as i used it to start up my old (crap ) pc. the new pc's specs are as follows

AMD athlon 64 3200
512MB ram
OLD 40 gig samsung HDD from my old rig.
Radeon 9600xt
epox 8kda
(supposedly) 400 watt psu.

When i attempy the turn it on , absolutely nothing happens<not even the fans spin up, even in the psu.

However. i was pullint out the mobo power leads while the psu was still on (obvoiously i didnt realise it was still on) Once i had taken out the 4 pin connecter, and was in the process of taking out the 20 pin power connector the trouble shooting LEDS turned on for a second or two.What do you guys recon?

Does anyone have any ideas?
I think it may either be that the POwer supply is not strong enough.Or that the MOBO is fried.


There are no visible burn marks or anything on the mobo.

Ok i jsut noticed that there is a capacitor down near the mobo chipsetthat gets really hot, when i turn on the psu, even though the PSU fans doenst turn on. Do you think if I connect the two capacitor pins then the pc might turn on??Or will something blow?


Is it possible that maybe that there is something wron with that capacitor? It heats up really quickly . It says EC5 beside it if that makes any difference to you.

Any and all help is much apprecitaed

cheers
chris.






sorry about the crap quiality.

[christophicus]

Re: MY pc wont turn on!! HELP!!!

Just checked. The capacitor is only rated at 16V 100 uF do you think it would be ok , just to connect the two pins of the capacitor?

[willawake]

Re: MY pc wont turn on!! HELP!!!

no that would make a short

did you try another known working psu?

[christophicus]

Re: MY pc wont turn on!! HELP!!!

Ive tried the PSU im using for that system in another PC , and it worked. I dont have another high wattage psu to try in the problem rig. I did try a 115watt psu and i suspect that was not a good Idea , however nothing happened.

Would I be right in thinking that it is odd that the capacitor is getiing quite hot, when nothing else is?

Also because teh capacitor is getiing hot, would that suggest that something before it is damaged?

[willawake]

Re: MY pc wont turn on!! HELP!!!

can you measure the voltage across one of the caps in the row near the cpu (need to take the board out and flip it over) you can check the voltage accross that small hot cap also.

[christophicus]

Re: MY pc wont turn on!! HELP!!!

Do you need a special device (a voltmeter?) to measure the voltage across the cap? I dont have one of those.

[willawake]

Re: MY pc wont turn on!! HELP!!!

yes. you can get one for about 5-10 euro. Here is a cheapie one (and a very common design) i think its a necessary item for the toolbox.

[christophicus]

Re: MY pc wont turn on!! HELP!!!

And will a cheapie one do? or are cheap ones really bad?I'll try and get one of those on monday.

[willawake]

Re: MY pc wont turn on!! HELP!!!

the above one is a DT-830B which is a very common design used by many manufacturers. i think its fine and very useful.

i cannot guarantee that it will be useful in this specific case but for the toolbox definitely i could not work without one.

[christophicus]

Re: MY pc wont turn on!! HELP!!!

Yeah ok ,cool , ill try and get one. Is there any other suggestions of anything i might try in the mean time?

[christophicus]

Re: MY pc wont turn on!! HELP!!!

You dont by any chance know of any retaillers in Ireland that sell it do you? Or anywebsites that might?

[willawake]

Re: MY pc wont turn on!! HELP!!!

i would personally have it out of the case with nothing unnecessary connected. i would not try another cpu until i have established that vcore is within acceptable limits in case the board is overvolting vcore.

did you see any burn marks on the atx connector?

other stuff i would try, i would use an esr meter to check all the caps esr (which you dont have) to establish whether there is some non visible problem with the caps. i would also replace that hot cap anyway to see if there is any difference then i could be sure that the caps are ok and continue troubleshooting.

[willawake]

Re: MY pc wont turn on!! HELP!!!

You dont by any chance know of any retaillers in Ireland that sell it do you? Or anywebsites that might?

you can find it in any store with electrician stuff (lightbulbs, fixtures, cables) or hardware store

[Tom41]

Re: MY pc wont turn on!! HELP!!!

If the PSU turns on fine with a different motherboard, it's probably okay. I had a PSU that kept making a 'sparking' noise and refusing to start up, only outputting enough power to make the fans wobble slightly. In that case, one of the capacitors inside the PSU had vented.

In your case, with the PSU fan failing to start when connected to this motherboard, I'd be VERY concerned. The sparking I heard on mine sounded like something was shorted, so something on your board is probably shorting the power from the PSU to ground. Check for any unusual marks on the board - not necessarily burn marks, but traces exposed/cut from botched repairs, any small pieces of metal on the board etc.

When capacitors fail they do sometimes short (like putting a wire across the two pins). It's perfectly possible that the caps on the motherboard have actually failed without any physical signs. Teapo, for instance, are notorious for doing that - what brand are your caps?

[christophicus]

Re: MY pc wont turn on!! HELP!!!

Willawake, there are no burn marks on the ATX connectors.
This ESR meter you speak off , is that one of the funtions of the multimeter you suggested to me ?


YEAh the caps on my board have Teapo written on them, i didnt realise that was the brand . Damn, things arnt looking good are they?

[willawake]

Re: MY pc wont turn on!! HELP!!!

esr meter is this one. its not going to be worth getting one for just one repair.
https://www.badcaps.net/forum/showthread.php?t=1287

tom is right, check for trace damage from a bad installation, although in that case i would be suprised if it had that and the board was doing nothing at all.

when you get your multimeter you can check to see if any fets are shorted (the three legged boxes)

[christophicus]

Re: MY pc wont turn on!! HELP!!!

Ok cheers, I went to homebase today, and they only stocked one multimeter and it was €55 . I couldnt really afford to spend that much money on somehting Im only likely to use to fix this board. Hopefully tommorrow i will get a chance to try another place though.And (figers crossed) they will do cheaper ones.

Im fairly sure its not the fault of a bad installation. I think we can rule that one out.

I really appreciate all of the help you guys are giving me.

cheers
chris.

[Spacedye69]

Re: MY pc wont turn on!! HELP!!!

Wait till the disease called Walmart spreads to your area. They have them there for around 12-15 USD.

[willawake]

Re: MY pc wont turn on!! HELP!!!

wait until the pakistani street vendors come to ireland. i got one with temperature probe for 5 euro

but yeah they can cost up to about 200 euro and over especially if they are called fluke (hello tiresias)



this one is really cool cos the probes are designed to fit in AC sockets. actually its not even mine, its my dads, i think i have some explaining why its in my toolbox.



shit i even have one called "ireland" lol

if you dont have one of these you are just not cool in my book.

[linuxguru]

Re: MY pc wont turn on!! HELP!!!

The cheapest Chinese-made ones around here are about the equivalent of $2. There are better ones with audible continuity checker, transistor hFE tester, capacitance ranges, etc. for about $6. We also get Goot ceramic-tipped plain old soldering irons (without any temperature control) for $4-$5, new in original packaging. If they're fakes, they're very good fakes - the workmanship is suberb, they haven't failed after about a year of heavy duty work, and the tips are intact without any chipping.

It sometimes helps to share a porous border with China - Lol.