System turns on but doesn't display video or make sound

pavlok

Distinguished
Jun 7, 2010
2
0
18,510
Hello,

This is my first ever attempt at building a system so I please excuse any beginner mistakes. I did go through the sticky on this forum regarding the issue I am having and I read the list several times to make sure I did not miss anything.

Here are the components of my system

GIGABYTE GA-P55-USB3 LGA 1156 Intel P55 USB 3.0 ATX Intel Motherboard
Intel Core i5-750 Lynnfield 2.66Gz LGA 1156 95W Quad-Core
Corsair XMS3 4 GB PC3-12800 1600Mhz Dual Channel
EVGA nVidia GeForce 9800GT 1 GB

After connecting all the parts to the motherboard I first attempted using the PSU that came with the case which is the LOGISYS Computer PS480D 480W ATX12V Power Supply but the system did not start at all. I therefore took a PSU I had from a different system which is the NZXT PP800 Performance 800W ATX Power Supply. Once I attempted this the system turned on and all the fans began working. I should point out that when I connected the 480W PSU the motherboard made a popping noise, I figured this destroyed the motherboard but it seemed to work after. I connected a motherboard speaker and the system makes no noise. I have went over the motherboard manual and searched the web for awhile now and still no success. Any help would be greatly appreciated.

Thank You.
 

banthracis

Distinguished
Um does the system work with the 800w PSU?

If it does you've answered your question already...

Check the MOBO to see if any capacitors are blown. You'll see them bulging with brown stuff leaking out of them if the are.

Next time don't skimp on the PSU, getting a bad one is the perfect way to fry an otherwise good system.
 

scooter69

Distinguished
Sep 29, 2009
157
0
18,710
I'd have to agree, get an Antec, BFGtech or CoolerMaster power supply. There are a lot of good PSU just read the reviews of oters, I've found newegg.com to be of great info for research. One thing to look for on the PSU, make sure the little red selector is on 110V if that's the standard in your area. Iv'e gotten some that have been set to 220V and the standard here is 110V. All that I've seen are selectable. Check to make sure the cpu is indeed in the right way and the 4/8 pin power plug is pluged in along with the 20/24 pin power plug. It never hurts to double check everything. It's the pits but everyone get a bad board and has to send it back (RMA it) for another one at some point or another. Another thing, make sure your board speaker/buzzer is in fact hooked up right, I've gotten boards with four pin header and a two pin connector, I just pulled them apart to hook up as needed. The buzzer can tell you a lot about what's happening, IMHO. Hope it helps and good luck.
 

pavlok

Distinguished
Jun 7, 2010
2
0
18,510
I checked the motherboard and there isn't any signs of damage on it. It looks exactly the same as how it did when I received it. What other methods can I use to see if the motherboard is causing the issue?

I am a little unsure of what power plugs should be plugged into the motherboard. The only way the system starts is if the 24 pin connector is in by itself. If I plug in the 8 pin connector in addition to or just by itself, the system does not start.

I have tried to plug in the motherboard speaker several different ways and it still fails to make any type of noise.
 

garrett1986

Distinguished
Jun 8, 2010
66
0
18,660
2 things you need to do.

1 take a digital or analog multimeter and check these

http://www.smpspowersupply.com/connectors-pinouts.html

if your psu is broken you will find out through a stray line.

2 check your ram

- if a ram stick isnt all the way in/broken or otherwise not in working order. it will cause exactly the symptoms your talking about IE no video post, no sound, random reboots, or system refusal to even power on.

3 one by one if neither of those work check each individual component with a known good one. even if the known good one is crappy, it lets you know if a particular part is not in working order.

http://acmehowto.com/howto/pc/problems/diagnosis.php

basic pc diagnosis guide. let me know how it goes.
 

There's at least one of your problems. The 8-pin connector provides power to the CPU. Your computer will never work without both the 24-pin AND the 8-pin connectors plugged in. There's a link to our troubleshooting sticky in my signature. The sticky was created to troubleshoot this exact type of problem. Let us know how it goes after you've performed EVERY step in the checklist. I know you said you went though the checklist, but you obviously didn't perform every step if you don't think you need the 8-pin connector plugged in.