HELP!!!!! Build finished - computer won't start.

[chiefgabbai]

Just finished building my new PC, but when I plugged it in and turned the switch on the power supply absolutely nothing happens. Pressing the power switch on the front of the case does nothing either.

I am using Gigabyte DS3 mobo with FSP 450w PSU. I plugged the 20-pin molex into pins 1-20 of the mobo and the 4-pin molex into another plug on the mobo (at the top). I wasn't sure if the 4-pin was oriented right.

Any thoughts on what to try next? Is the 4-pin supposed to be plugged in?

Thanks.

 

[Howard_Stern]

The plug ins from the PSU should allow for just one way to plug them in. I doubt that you were able to plug in the plugs in the wrong orientation.

Nothing comes on? Does your MB have an LED display or any kind of lights on it at all?

Dead PSU? Or maybe the switch from your cases is not hooked up correctly.

Does the fans on the PSU spin?

 

[chiefgabbai]

Or maybe the switch from your cases is not hooked up correctly.

You probalby just dont have the power sw pluggin in correctly.

What switch are you talking about? Is that the tiny 2 wire plug that comes from the front of the case or are you talking about something else?

I don't see any lights on the MB and I didn't see anything spinning at all. Should the PSU fan spin just by the PSU being plugged in and switched on?

Thanks.

 

[cdonato]

most likely the wires for the case controls are connected to the mobo header wrong. they are usually the culprit for that type of stuff especially since half the time they aren't labelled so its a guessing game to see if the switches & activity lights are working properly

 

[chiefgabbai]

most likely the wires for the case controls are connected to the mobo header wrong. they are usually the culprit for that type of stuff especially since half the time they aren't labelled so its a guessing game to see if the switches & activity lights are working properly

I hope you're right. I will check again tonight. Would that actually cause NOTHING to spin?

Can I assume that the white wire is negative and the color wire is positive?

 

[chiefgabbai]

Yes it would cause nothing to spin if the power switch isnt hooked up correctly LOL. No power = No spin!

Well duh!!! ;-) I knew that, what I meant was that I would have expected that plugging in the PSU would at least cause the PSU fan to spin.

I appreciate your help. Please keep it coming.

 

[Alyarbank]

The power switch connection completes the circuit along with the mainboard, and the fan in the PSU will spin. If you were to plug the PSU in the wall by itself it does nothing, unless you jump the green wire to a ground wire.

Most likely you have the power switch from the front panel backwards.

 

[chiefgabbai]

Thank you all for your pointers. I will check it out when I get home tonight. If I assumed incorrectly that the color wire is positive and white is negative, switching it should be OK, right - I guess it might bring my PC up

 

[chiefgabbai]

You probalby just dont have the power sw pluggin in correctly.

Are you referring to the 3pin Power LED header? Does this come off the PSU?

 

[chiefgabbai]

Sorry for the long post. OK, I am stumped. There is a configuration like this in the corner of the MB.

F. PANEL
.
. 1 . . . . _ _ . . . . 20
. 2 . . . . . _ _ _ _ _ 19
|
|
V
PWR LED

. denotes a header pin; _ denotes a blank on the header. I can't get the pins in my diagram to line up, but you get the picture.

Pins 1/3 - IDE Hard Disk Active LED
Pins 2/4 - MSG LED/Power/Sleep LED
Pins 5/7 - Reset Sw
Pins 6/8 - Power Switch
Pin 9 - NC (not sure what that is)
Pins 14/16/18/20 - Speaker

Pins 1, 2, 6 and 7 show + the others -. I have NOTHING that would plug into the vertical 3 pin PWR LED. The POW LED that I have are two single pins (+ and -) that I assume are plugged into pins 2/4. Should there be anything to plug into the PWR LED 3pins?

My ATX molex has 20 pins and there is a separate 4pin molex that says Pins 11, 12, 23, 24. I assume that these go into the 24 pin plug along with the 20pin plug. In addition there is a 4 pin molex that I am assuming is the ATX-12V connector. I have all those plugged in.

The case came with a fan with 3pin connector as did an optional fan that I bought. I plugged the incl. case fan into MB PWR_FAN header. The PSU has a set of wires with 2 4 large pin connectors in series and a pigtail with a tiny 4 pin connector. I plugged the opt. case fan into one large 4pin and plugged the pigtail into header called SYS FAN. Is that right?

I appreciate any and all help you can provide.

 

[LabaR]

does your 3 pin thingy on have 2 wires going to it? I'm not quite able to follow what your trying to type, well i know what your trying to explain, but i'm not following. your pins go in parallel with the strip, you don't put them in crossing over from 1 row to the other, at least thats how every mothers board i've ever had has been.

 

[GSTe]

Sorry but this is quite hard to follow about which pins are where, etc. If you look in your MB manual it will show you the layout of those pins on the header, and which are used for what. Just plug the power switch wire onto the 2 correct pins. If it doesn't work then try it the other way.

If your power supply is working then it should light the LEDs on your Mobo without the power switch wire having to be attached.

 

[chiefgabbai]

Guys, appreciate your attempt, but it didn't help. The MB manual is very sketchy and the connectors don't show which is + and which is -.

Can someone address my other questions re: 20+4 pin connections and the case fan connections. I still can't get anything to power up.

Also, I don't see an LED on the MB. Any thoughts on where to look?

 

[chiefgabbai]

I unplugged everything but the essentials and EUREKA- the system came up.

Now I have to get the BIOS set up (wish me luck) and connect all the peripherals and find out what caused the system not to start.

Thanks.

 

[PC_Side_Line]

....glad to hear u got it working, yes motherboards have extremely small lettering over in the jumpers and terminals area.

yes, if your case had many white wires then those would be the negative, and the colored wires would be the positive.