Put everything together but the system wont start :(

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blue-lynx

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Guys, i just put the system together but it wont boot.

motherboard = Gigabyte MA790GP-UD4H
Power supply = Corsair VX450W

I dnt know if I have connected the power cables wrong.

the power button on the case lights up when i turn the power supply on.

but when I press the same power button to start the pc, nothing happens.

I dont know what I am doing here...

please help!
 
Do you have:

The 4/8 pin CPU connector in? (it will be near the CPU socket)
The 20/24 pin motherboard connector in? (could be anywhere on the motherboard, likely towards the front of the case)

And stupid question but is the RAM in?
 
can you give a detailed description of you system? ie: cpu, ram, vid card, etc etc?

that will help some with a diagnosis.

Now, step by step, check your connections, if they're all connected properly, does your motherboard beep?
if so look through your motherboard's manual for that code and it'll tell you the problem.

although to me it sounds like the processor wasn't installed right or even could be a lemon
(assuming the CPU is the right socket)
 
okay so here's what happened...

i took the motherboard (gigabyte) with the cpu seated on it, plus my ram sticks to the store.

the store guy simply took out the battery and wiped it or something (cmos battery) and then with the motherboard on the table he just hooked it up to a generic power supply and touched the front panel pins with a screw driver and suddenly the cpu fan started moving full blast.

he said its all good now, maybe you had shorted the mobo.

i am puzzled, what did he mean by that?

also, i am back home with the cpu in its place just like at the store and the ram sticks in.

however.. when i hook it to my power supply (got two, one is enermax and one is corsair) its the same issue again.

the motherboard wont turn on.

could it be the powersupply?

also to be noted, the case's power led turns on when i put it my motherboard but when i hit the power switch button on the case, the motherboard wont start...


Edit: the cpu cooler wasnt plugged in right when i took it to him but after he plugged it correctly, i dint touch the cpu heatsink, just got the motherboard home.. put into the case and the same problem persists..
 
It sounds like the power supply, yes. You're getting some juice (mobo lights) but not enough to power everything up. Regarding the heatsink, do you mean you didn't attach it to the CPU ? You definitely want to apply thermal paste and attach your heatsink. Overheating isn't good as you well know I'm sure.
 
my money is on your shorting out somewhere as said "repairman" stated.

and what he means is that some where along the line a "hot" lead (the path/wire that carries the 12v-5v input current) is touching metal in your case, why is this bad?

Because unlike a house 12v DC relies on a single path.
Ac input-> power supply-> 12v or 5v current -> (place device here) -> ground loop -> power supply

when the hot lead is touching the metal is basically the same thing as touching 2 120v AC "hot" leads together ( better known as arcing a circuit) and this can fry anything that is now touching metal, now you may not feel this when you touch you case as the PSU is active because it takes some power at 12v DC to be felt by a human.

when he said "shorting the motherboard" you probably didn't install some/all or the risers. if so you definitely need to.

Now take everything I say with a pinch of salt, I am by no means an electrician but I've dealed with enough of the simple wiring of life (both AC and DC) that I have a faint basis in electron theory.

You can troubleshoot this with a multimeter.
yellow_multimeter.gif

this is a multimeter if you didn't know.

like I said I'm no pro but it's just my $.02
 
Your power switch may be dead or attached to the wrong pins

Your mobo may be grounding out if it's not in the case properly. Take it out of the case and hook it up and see if it starts. If it works you'll need to check the stand-off's for proper positioning, extra stand-off's with no corresponding mobo holes is bad. No stand-off's are bad.

Or both of your power supplies maybe bad or inadequate.

What are your complete system spec.'s?
 
Well you could have had a short (a second time) because of the standoffs not being installed properly, but had you in fact installed the mobo back in the chassis when you tried it a second time (when you got back home) ? You could take it back out of the chassis and recheck your standoffs. Wouldn't hurt to check again, like missing or loose ones. Make sure they are all there and tightened.

Other than that, I am still thinking PSU.

EDIT: Slaymate has a good point about the switch as well. The Radio Shack guy bypassed that switch because you had it at home in the case. So he started it that way. But a bad switch could be a reason it won't start.
 
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