Need Diagnosis Help

[roundsound]

This build is about a month old and was working fine, all components are new. Last week I turned it on and got sparks and smoke from the power supply. After that it wouldn't start so I got out my multimeter and began checking voltages on the board. The s bridge led will light when power supply is turned on. When I checked the power switch terminals the board started and the fans started working. I had made the connection, but the power switch would not start the board. However, I got no video. I did not have a speaker plugged in.

A few days later I was going to wire up a speaker and count the beeps but now the board won't start under any conditions.

Here are the details:
1. Power supply fried, board wouldn't start.
2. S Bridge led will light.
3. Board did start once when power switch terminals were connected but no VGA. Will not start now.
4. I reset the CMOS during diagnostics. No help.
5. I replaced the RAM stick.
MB=ASUS M4A88T
RAM=GSkill DDR-3 1600
PS=Zumax 550 watt.
Case=1 unit rack mount server
CPU=AM3+ 3 core 2.8 mhz

How can I test the MB to see if it is fried? Any other suggestions are appreciated.

Thanks!

 

[Swolern]

Did you get a new psu to test with?

Buy a brand name psu. Zumax is crap.

Have you checked for wall line stability? You should be getting a constant 120v, (+-)5% during load.

 

[MotherFerJones]

apart from getting a new power supply an popping it in, there's really not alot of ways to test the M/B other than physically putting it under power and seeing if it works. If you have any computers laying around that you dont mind scavenging from then try the power supply from it, and see if your system starts with the basics, CPU, M/B, 1 RAM stick.

 

[MotherFerJones]

as far as PSU's go when searching for a new one, type in "PSU tier list" in a google search and you should find a newegg forum post about PSU tiers and what Brands/Models fall into each tier.


EDIT: misspelled should, almost misspelled, misspelled, lol

 

[jemm]

Last week I turned it on and got sparks and smoke from the power supply

CORSAIR Builder Series CX500 V2 500W http://www.newegg.com/Product/Product.aspx?Item=N82E16817139027

 

[roundsound]

Yes I installed a new PS but the only thing available in this small town with a fan in back is Zumax. But it will do for diagnostics. I'll get a decent one from newegg later.
Swolern-I have good power.


Is there somewhere I can test a voltage on the MB to tell if it's fried?

 

[roundsound]

Nice PS, jemm.

When you get smoke and sparks from a PS it is obvious that it's fried. I would never consider using it for anything but landfill bait.

Thanks for the help everybody. Keep it coming!

 

[Swolern]

There is no single way to test the motherboard, they have hundreds of components to test. Easiest thing to check is for bad capacitors, happens a lot. They'd be puffy or actually burst at the tops.

Aside from that, you'd have to basically learn how the motherboards work, what part should have what voltage, resistance, etc..., and start checking them. Plus they are usually built in layers, have different other chips on them aside from the CPU. Good project to play with if you really want to do this, but don't except someone to say "just hook up wire A to part 1, wire B to part 2, if you get no reading it's bad".

Overheating from a faulty power supply is probably the biggest cause of an overall fried motherboard. Sometimes---but not all the time---you will notice physical damage to the motherboard itself, including burn marks or fried capacitors.

 

[roundsound]

Thanks Swolern. So, the PS fried and the MB didn't work correctly after that. So is it possible that the PS sent a voltage spike to the MB and that is what fried the MB.

Or did a bad MB cause the PS to fry?

Probably could be either, I'll wager.

 

[roundsound]

I tried replacing the CPU and RAM and the MB still won't start. The PS is new but a crappy brand but there is voltage to light the south bridge LED.

MB seems to be the problem. Anybody disagree?

 

[Swolern]

I tried replacing the CPU and RAM and the MB still won't start. The PS is new but a crappy brand but there is voltage to light the south bridge LED.

MB seems to be the problem. Anybody disagree?

Im afraid it looks like it.

 

[jemm]

It seems your old PSU broke your motherboard.

 

[roundsound]

Thanks everybody! I got an RMA from ASUS so the MB is on it's way back. I'll let you know how it goes.

 

[jemm]

You are very welcome!