easy question

[imgodlike1]

hi everyone,
i'm setting a computer up for the first time, and i have 2 questions:

1) if i don't have a cpu installed in the mobo, will there be no video when i power up the system? i'm putting the computer together and waiting on the cpu and i decided to test out what i setup, it powers up, but nothing on the screen. is this normal when there's no cpu, or is it supposed to go into bios even without a cpu????

2) a friend took my working computer apart, and now after its back together, it won't power up when he hits the power button. needless to say i'm pissed, but i'm reaching out for possible help here. the motherboard in this computer has the green light saying that its getting power when the power cable is plugged in, but nothing happens when i hit the power button.

thanks for the help everyone.

 

[SquishyWeasell]

1) That is perfectly normal. Without the cpu the computer cant get anywhere - it cant even post. In order for a comp to post it needs a motherboard, video card, ram, and cpu

2) Its possible he forgot to connect the power button back to the motherboard. Its a little wire that comes from the power switch that has to be plugged in the correct place on a little array of pins on the motherboard.

I hope that helps!

 

[OdiN]

Originally posted by: SquishyWeasell
1) That is perfectly normal. Without the cpu the computer cant get anywhere - it cant even post. In order for a comp to post it needs a motherboard, video card, ram, and cpu

Well...not 100% true. A board can POST with just the motherboard and CPU. It does not need a Video card or RAM in order to initialize the POST process...it just can't complete the POST without them as in either case it will get to a point where it tests video or RAM, and then output the proper POST fault code (a series of beeps) to tell you there is a problem. I admit this is a bit of a nit pick, but technically true

As for the second computer, yeah see if the case's power switch is connected to the proper pins on the motherboard. He might have missed it by one pin or something. You'll need your motherboard manual to figure out which ones are which most likely.

 

[SquishyWeasell]

im gonna test that out tomorrow. I wasnt sure about the video card, but i thought it needed ram to post.

 

[dudeman007]

Yeah I agree about the power button. They are very easy to mix up. btw...why did your friend do that!? "my friend took apart my working computer"....yeah...smart

 

[imgodlike1]

well from the looks of it, it doesn't appear to be the power button, my stupid friend decided to take apart my working computer when i was putting together my new computer for something to do. he said he's done it before, but now its looking more and more like he's about to pay dearly for his mistake since i may have to take it to a computer shop if you guys don't have any clue what it could be other than the power switch on the mobo.

 

[tomstevens26]

Exactly how much did he take it apart? Did he go so far as to unmount the motherboard? Maybe you're getting a short some where? Also, make sure the power connector going to the floppy is correctly attached (i.e. not skipping any pins). I did that once and the PC wouldn't power on. Good luck!

Tom

 

[Jeff7]

Originally posted by: imgodlike1
well from the looks of it, it doesn't appear to be the power button, my stupid friend decided to take apart my working computer when i was putting together my new computer for something to do. he said he's done it before, but now its looking more and more like he's about to pay dearly for his mistake since i may have to take it to a computer shop if you guys don't have any clue what it could be other than the power switch on the mobo.

Other things it could be:
- Not plugged in
- PSU itself is switched off
- Surge protector is switched off
- PSU is set to 220V instead of 110V
- ATX connector not hooked to motherboard
- Supplemental power connectors, if needed, not hooked to motherboard
- Power switch plugged into wrong header

Though I just noticed you said that the board indicates it is getting power; guess that rules out the ATX connector; maybe it does need a supplemental connector though? Check around and make sure the motherboard doesn't need anything else, like that 4-pin ATX12V power cord.
But if the board is getting all the power it needs, it should turn on; just recheck that power switch header. Make sure that you don't have, maybe, the Power LED hooked up to the switch connector or something simple like that.

 

[OdiN]

Originally posted by: imgodlike1
well from the looks of it, it doesn't appear to be the power button, my stupid friend decided to take apart my working computer when i was putting together my new computer for something to do. he said he's done it before, but now its looking more and more like he's about to pay dearly for his mistake since i may have to take it to a computer shop if you guys don't have any clue what it could be other than the power switch on the mobo.

Check the motherboard, see how many and where the holes are that screw it into the metal standoffs to the case. Check the back side of the case (if possible) and count how many standoffs. Look to see if there is an extra one which would be shorting out the motherboard and preventing it from powering on. I see this more often than you may think. First time computer builders get anxious and start putting in standoffs, forgetting to check the motherboard. Sometimes the case comes with some installed that the motherboard you have won't line up with.

You are down to the troubleshooting mode if that isn't the case. Here is what you do. Make sure that power connector is rght for first. Then check your reset switch on the front of the case - make sure it isn't stuck in. Try unplugging the reset switch from the motherboard and seeing what happens. If all that fails try this:

Remove all unnecessary cables and cards. Have only the board, CPU, RAM, and Video card plugged in and try it that way. Unplug IDE/Floppy cables, unplug power from these devices as well. If it boots, start plugging things back in one by one and testing after each step. This will show you most likely what has failed or what was plugged in wrong. It may work fine after doing this. If all this doesn't work and it doesn't boot with Mobo/Vid card/RAM/CPU, then it is a power supply problem, or grounding/short probelm. It could also be a damaged CPU...how far apart did he go?

 

[Metron]

I second Jeff and Odin's recommendations for checking the 4-wire ATX power connector from the power supply to the motherboard.

I've run into the situation you describe, no video, when that connection was loose or disconnected.

The plug is a square connector with four wires attached.

*edit* Picture of ATX plug, shamelessly copied from MechBgon's great build overview

Good luck,
Metron

 

[imgodlike1]

i just asked him, and he said that he did in fact take the cpu off. now i'm pissed, because i'm afraid that it might be that. if the cpu is damaged, would it prevent the computer from starting up at all?? that doesn't make sense. he didn't remove the mobo, he took all the cards off, disconnected all the cables, and took off the cpu. By the way, this was on a dell dimension if that means anything.

 

[DKlein]

So your friend took apart your computer just for the fun of it? Well I admit that can be fun, but I'd suggest not letting anyone do that again Having fried a few processors in my time, I think the system should still power on, it just won't do anything (blank screen) if I remember correctly. Like the other guys said, make sure everything's plugged in that needs to be, and be sure to check that header.

One highly probable thing that may have happened is that your friend, if ungrounded, might have shorted out some of the circuits on your motherboard, which would cause this I think also (this is why all your parts come in nice, static-free packaging). Did your friend make sure to ground himself properly before touching your hardware? He could have done more than just damage your motherboard also, depending on what he was handling.

 

[mobobuff]

Your friend doesn't sound like he knows too much about computers. Knowing how to take something apart means nothing. When I was 5 I could take apart pretty much anything, but did I know what every part did and how to handle it? No. Did they all work everytime after I put them back together? No.

Especially when dealing with computers, I'd say never take them apart that much unless you have a reason, when you have a reason you are a lot more focused and therefore much more careful.

I'd no sooner hand my computer over to a 5 year old then to a friend who just wanted to take it apart for the shits and giggles of it.

There are many causes of a computer not powering up, and they are all detailed very well by the people who've posted here, and you can also use the search at the top of the forum to find similar topics. After a lot of reading you should have a pretty good knowledge of all the problems that could be causing it. So all that's left is just to troubleshoot. If you do get it working again, congratulations and consider yourself lucky.

Actually, if you have a digital camera of decent quality, you could take a picture looking down directly at the motherboard, try to focus it as much as possible, and then link to it here, and there's a chance that we may be able to find a problem by looking at it. If you can't get the whole thing focused that well, take maybe 2 or 4 close-up pictures of separate areas.

 

[imgodlike1]

you all have great advice. i will troubleshoot it myself in the next day or two. if i happen to not be able to get it working. i have a pretty good digi cam that i can take pics of.

you have all helped alot. just so you know, my friend was taking my other comp apart in another room, i had no idea he was going to do that, i figured he was playing a game on it. he's all excited because he put a computer together himself the week before. i'm pissed at him, but hopefully i'll get it figured out and we'll both learn from it.

thank you again, this forum is an excellent resource.

 

[mobobuff]

Ahh! Don't leave that kid alone with a computer, ever! If he wants to learn give him old broken electronics to play with. Yeesh.