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Freshly built pc refuses to turn on

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March 19, 2009 2:54:12 PM

hello everyone, just got my new system set up and was getting ready to turn it on for the first time and... nothing :(  what happens is it flashes a light by the CPU and doesnt even turn on for a second. im not to sure what else to mention about it, i checked all the plug ins and everything seems to be correct and plugged in well, if anyone can help out i'd greatly appreciate it :D  thanks

-shawn
March 19, 2009 4:00:40 PM

It is shorting out somewhere. Recheck all connection are connected properly and in the right place. Take the mobo out of the case and try it, put it on the box it came in.
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March 20, 2009 1:11:35 AM

k thanks im trying all the trouble shooting tips atm.

a couple quick questions i had that might end up solving the problem and alot of headache over nothing.

first thing, i redid the cooler on the cpu, from a few things i was looking at i think i might not have made a good enough connection with the compound i put on there.
Another is i have multiple ways of plugging in my GPUs power to the set up. i can either plug it directly into the mobo or i can plug it in though the power supply, would one make a difference over the other? also on the GPU there is 2 6pin slots, do i need to power sources for it?

im using a biostar tseries ta790gx 128m mobo and a radeon hd 4870 1gig/256mb gpu and a mod xstream-pro 600w power supply. if anyone has experience with those components and can give some advice of what might be a good thing to look at that'd be awesome, thanks again

-shawn
March 20, 2009 1:16:26 AM

yeah man sounds like something is shorting out for sure, so after you reseat everything and double check your connections i would say things would be good, and dont forget to power your mobo, sounds like it isnt getting juice from your psu, there should be an additional power connection on the motherboard itself, and you have to plug both pci 6 pins for that 4870 to give it power it needs also.
March 20, 2009 1:17:49 AM

your gpu will not work if you don't give it power. You need to plug in the cables that are labeled PCI-E from your psu into the 6 pin plugs on the graphics card. Read the manual if you need to see how to do this.

Ya and what Jared says. Make sure the 4 pin mobo power plug to the upper left of your cpu on the MB is plugged in also.
March 20, 2009 1:27:27 AM

there is onboard graphics on this mobo, could i try to get it to run without the GPU firs to eliminate that as a problem, i'd hate to be focusing on getting the gpu to work if its something compleatly different causing it to not boot up. well im getting everything back in it right now and i'll let ya know if i get anything different with the couple changes i made
March 20, 2009 1:30:28 AM

Yes try that to see if it will post.

Also sometimes you have to change a setting in the bios to get the MB to read the gpu card over the on-board.
March 20, 2009 2:13:13 AM

well after getting it all back together im still having the same problem, the leds on the fans flash for a sec then it just stays off like its not getting any power. ive doubled checked all the connections and as far as i know they are all correct(followed the mobo manual step by step). i tried taking out one of the sticks of ram and booting that way, no luck. the only real thing i think of that would be wrong is the connectors from the power supply to all the componets. theres 3 plug ins that come out of the power supply, a 4pin one that im pretty sure is the cpu power, a 20pin one that has a optional 4pin with it that im pretty sure is the mobo power(tried with just the 20pin and then with that and the 4pin, neither way works. and theres an 8pin connector that i think is also for the cpu, but my mobo only has a 4pin available for the cpu power so i shouldnt have to worry about this one?

as for the sata spots i have the hdd and dvd drive into slot 1 and 2 and for there power they're running though the power supply with the same cable(should they each have there own or should this be fine?)

i tried taking out the mobo battery to reset it(i think thats how you do it? lol) and it didnt help anything.

well im just about out of ideas on what else i could do, thanks again for all the help and baring with me i really do appreciate it, this is my first build and other then a couple IT classes i took in high school im way noob with all this stuff :p 
March 20, 2009 2:19:13 AM

well man my suggestion would be to take the rig up to a local shop and ask them if they could test your setup with a psu they might have laying around, from the sounds of it its your motherboard or psu that has bugged out. in which case, time to rma.
March 20, 2009 2:29:20 AM

For the mobo, do you have something plugged in the 4 pin plug or not? you need to have the matching psu cable plugged in there it should be a 4 pin connector or a 8pin but does not say PCI-E on it.

Either the mobo is not correctly connecected to the psu or you have a short. When you put your mobo into the case did you use the stand off screws so you mobo is not resting on the backplate?

If you don't know what I am talking about, please bring it to a local pc shop.
March 20, 2009 2:40:30 AM

caniba said:
For the mobo, do you have something plugged in the 4 pin plug or not? you need to have the matching psu cable plugged in there it should be a 4 pin connector or a 8pin but does not say PCI-E on it.

Either the mobo is not correctly connecected to the psu or you have a short. When you put your mobo into the case did you use the stand off screws so you mobo is not resting on the backplate?

If you don't know what I am talking about, please bring it to a local pc shop.



yeah i have the 4pin plug from the psu plugged into the 4pin connector thats right above the CPU. i have the longest plug in(the 24pin) plugged into the only spot it could possibly go into. none of the cables comiing out of the psu are labeled but they should just go where they fit right(there isnt multiple spots for the same plugs so im pretty sure its right)?

yeah i have 6 spacers( not more then there are holes in the mobo for) proping up the mobo from the case.

is it a possible cpu problem or would it be doing something different then just not booting at all if that were the case?
March 20, 2009 2:50:03 AM

possibly cpu, but I think it is the mobo more than anything else. Did you try it with the on board video? Make sure you are trying this with the bare minimum, 1 ram stick, no cd/dvd drive, etc. If that doesn't work then you are pretty much out of options. you will have to rma the mobo.
March 20, 2009 4:06:00 AM

yep just did it with no drives and all on board as much as i could and still the same thing, so do you think the power supply is more then likely fine and the mobo was just faulty from the start?(i was real careful about grounding myself before touching anything, thats one thing i remember from before lol)

as for the cpu and cooler being connected with that thermal paste, what do i do with the old stuff? do i have to remove it before putting new stuff on and how do i get it off because i would assume soap and water isnt the best route? heh
March 20, 2009 4:58:10 AM

hmm well you can buy some cpu surface purifier, for around 5 bucks, but my suggestion to you would be to go to a local shop and have em check it out, they shouldnt really charge you anything if you talk to em real friendly like =) haha
March 20, 2009 5:26:14 AM

check to see if you put the mounting spacers in between your motherboard and your case. You will not believe how many 1st time DIY do this mistake.
March 20, 2009 5:41:17 AM

Yeah mounting spacers, just about to say that lol. Cause that was the problem I encountered when I made my first, second, and third tower >.>; (never had enough of those in box)
March 20, 2009 5:53:27 AM

you forgot to plug in the psu
a b B Homebuilt system
March 20, 2009 12:30:44 PM

Take the board out of the case, put it on a piece of cardboard.
Just the board, on-board graphics, CPU/heatsink, and 1 stick of memory.
Hook up all the power cables, monitor, try that first. If you get into the POST screen, remount the board and try again, keep adding 1 thing at a time until you either are up and going, or find the offending part.
March 21, 2009 12:16:59 AM

yep have 6 mounting spacers evenly spread out and the mobo is not touching the case at all. tried the having the mobo out of the case with just bare minimum and still nothing, im just gonna rma the mobo cuz i do have a warranty for like 30days or something and i'd have to wait till monday to go to a comp shop. i live in a really small town and there is like only 1 computer shop here and are way over priced on everything and would probably charge me to even take a look at it : /

April 4, 2009 1:32:28 AM

well just got the new mobo back from newegg.. tried booting with it out of the system before i even put it in and im still having the same problem with just the leds flashing for a sec then it stays off. so does this mean it was probably the power supply from the start? appreciate the help, thanks to who ever can help me solve this >_>
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