New PC won't power on 1

[ttechie]

I've just assembled my first PC, and it won't power on. I've checked all the connections and everything, but when I push the on button nothing happens.

I was talking to a collegue, and they suggested that because I'd bought a Taiwanese motherboard and American CPU I needed a Gra-rad modifier between the power supply and motherboard.

I've tried searching for it and can't find one anywhere. I've asked other people at work and they said I should find one on ebay, but I can't. I even asked at my local computer store, and they didn't know.

I'm beginning to feel like I've mated my money.

Any help is appreciated.

54 going on 55...

 

[ski]

Hmmmm.....
Sounds like someone is pulling your leg.
Just about every MB is made overseas, so what you're being told makes no sense.

Install/connect only the power supply, MB, CPU, memory, video card, monitor, keyboard, case speaker, and power button, and make sure the power supply's voltage selector switch is set to the correct voltage and the PS connection to the MB is securely seated.

If there's no display, then clear CMOS with a MB jumper, or by removing the CMOS battery for at least 30 minutes.
If that's already been done, then make sure the 'Clear CMOS' MB jumper is not in the 'Clear' position.
If the jumper is in the proper position, then check the CMOS battery for the correct voltage(3V).

If no luck, then place the MB on a piece of cardboard. If there's now a display, then the MB is shorting out when installed in the case. Check for a loose screw, standoff, etc., inside the case, and also remove any standoffs which do not line up with MB holes. If none is found, then remove all MB screws and metal standoffs, and install paper washers(manila folder paper works good for this) between the MB and the screws/standoffs.

If there's no display with the MB placed on a piece of cardboard, then proceed with the following:

(1)If the MB standby LED does not light up when you turn on the power supply's switch, then check the wall outlet, surge arrestor, and power cord for the correct voltage.

(2)If the voltages are ok for the items in (1) and the MB standby LED still does not light up, then then slightly raise the PS main power connector out of the MB connector a little. If the MB LED lights up, then the connector on either the PS or the MB is bad. If the MB light still does not come on, then the PS or MB is bad. Swap these 2 items out to find which one is bad.

(3)If MB light comes on, but the PS fan, other fans, and other lights do not work when the 'Power On' button is pushed, then make sure the computer case power button's wires are securely connected to the correct MB terminal(POW-ON, Power On, etc.), and that the wires are not shorting out(bare spots). If that's ok, then remove the power button's wires from the terminal, and momentarily short out the MB terminals with a screwdriver. If the fans and lights now work, then the 'Power On' button assembly is bad.

(4)If the fans connected to the MB and all other lights do not work when the MB 'Power On' terminals are shorted, then either the MB or PS is bad. Either swap them out, or have them shop tested to find the culprit.
If you have a voltmeter, then you can test the PS with the steps described here:

http://www.ochardware.com/articles/psuvolt/psuvolt2.html

 

[ttechie]

Thanks for that. I've not been in work today, so can't check if the lads are having a joke. I wouldn't have thoguht so though as, they're usually quite firendly and helpful.

I've done as suggested and re-taken my motherboard out. Are you sure I've got to sand all the silver points down on the back of the motherboard? They're quite tough, and I thought that was fairly common. Can't I just put it back in the case with some cardboard under it? Will a cereal box do, as the corrugated stuff is a little thick.

Anyway, I laid everything out on some card, as suggested (I had quite a job keeping the dog away, it kept trying to sniff it, daft thing), and plugged everything together and tried tunring on. Nothing happened again. I've noticed the power fan comes on. There is no light on the motherboard so I don't know if it's working. The CPU fan came on for a couple of seconds, then stopped (good job really as the dog nearly stuck it's nose on it), so I guess that's something. I don't think I've plugged anything in wrong as everything seems to only go one way round.

At this point I took the dog out of the room, as I was fed up with it getting near the whole lot. When I came in I stupidly knocked my tea over and it spilt over the power unit, there was quite an alarming blue flash, loudish crack and a puff of smoke. I quickly uplugged it from the wall socket. It's currently sat next to the radiator drying out.

I'll give it another go tomorrow, once the unti is dry, and see if I get any further.

Thanks for your help ski. Once I get this working, I'm going to build one for my grandson's birthday in a couple of weeks.

Thanks again.



54 going on 55...

 

[ski]

You're welcome.

I would not use that power supply. A blue flash is not a good thing.

WRT the CPU fan running momentarily and then stopping, if the MB's CPU fan terminal has 3 pins, then make sure the CPU's fan connector is connected to the correct MB fan terminal.
If it is, then make sure the CPU's fan connector is a 3 pin design. If it's not, then get a fan with a 3 pin connector. The 3rd pin is a speed sensor, and the MB's BIOS may have a feature that shuts down the system if it detects a CPU fan failure, which is what a 2 pin connector will simulate.

If the CPU's fan has a 3 pin connector, and it's connected to the correct MB fan terminal, then make sure that thermal compound has been supplied to the CPU-heatsink interface. If there's a thermal pad in lieu of compound, then make sure the cellophane cover has been removed from the pad.

If those are ok, then either reposition a MB jumper(see MB's documentation), or remove the CMOS battery for 30 minutes to reset CMOS.

If still no good, then the CPU or MB may be bad.
And I think we both know what the PS's situation is.

 

[electronicsfreak]

Check the back of the power supply, ensure its switched to 110 if your using a 110.

 

[anthony99]

sounds like the psu is duff well it will be now after spilling ur tea over it............i wud have said check the pins where ur on/off button goes to on the mb they can be a bugger to get right sometimes!

 

[paparazi]

Blue flashes and puffs of smoke from a PSU is not good! I would say this PSU is likely dead now and you need a replacement rather than risking other components further (infact this could already have damaged other things ie Hard drive, Cdrom etc)
Martin



We like members to GIVE and not just TAKE.
Participate and help others.