Need help with motherboard issues

[limsgp]

My Build
MB: MSI B250M
PSU: Seasonic x850
CPU: i5-7600

Background:
My DIY computer was running fine for 9 months then suddenly 1 fine day it suddenly powered off and cannot be turned on anymore.

During troubleshooting, I took off all components (no CPU, RAM, nothing) from the MB except the power, and the observation is as follows

1. ATX 24pin connected, CPU 8 pin power not connected. I was able to power on the MB (by shorting the PW switch), and the white strip light remains on until I power it off (by holding power switch for a few seconds)

2. ATX 24pin connected, CPU 8 pin power connected. Not able to power up at all.

Test was done outside of the case on a cardboard surface.

According to MSI support, seems like the CPU power supply capacitor is defective. Any advice on how I may go about identifying the faulty capacitor(s) if there is no clear indication of blown or budged capacitors? (i.e. can't tell physically which capacitor is bad)

Thank you for any kind advice and assistance.

 

[Darkbreeze]

Is this board no longer under warranty? When was the purchase date and what is the actual model number?

B250m is only part of the model number.

This document seems to indicate that all MSI motherboards have a 3 year warranty, and if that board is still under warranty there is no way I'd recommend trying to fix or further diagnose the problem yourself. Send it to them and let them replace it with a new board.

http://www.msicomputer.com/html/popup/CustService/General_war.html

 

[limsgp]

Oh, its B250M Pro-VDH. Possible to advise which are the capacitors related to the CPU power supply?

MSI ask me to contact the local service center. But the local service center refuse to attend to it because I bought it from online and they claim that MSI don't offer international warranty. I believe for warranty support shipping will be own cost. The shipping to US would cost more than a new MB so it is not a viable option. Hence I have no choice but to try to fix it myself.

 

[tejayd]

As dark breeze said, if it's under warranty don't mess with it. Did they mean mother board capacitor? Or PSU? If you had another psu I would try that anyway.

Blown capacitors can be hard to spot. Or even show no signs they are bad. Dark spots on the top are a give away. You can even try taking a photo of them on your phone and zooming in. Tilt it, so it's not straight down. The "bulge" may be smaller than you expect. And there may be more than one in the same area.

 

[limsgp]

Its as good as no warranty. It is not used in the country it was purchased in.

Already tested with another PSU. Same observation.

It's a tier 1 PSU.. I seriously doubt its the PSU..

It's the MB capacitor. Basically, MB has 24pin ATX power source and 8 pin CPU power source right?

The MB cannot power up only when the CPU 8 pin power source is plugged in. So it's the MB CPU power related capacitor causing the problem.

 

[Darkbreeze]

What do you mean by tier one PSU. PSUs that some people think are on tier 1, like the LTT tier list, are junk, and don't belong anywhere above tier four, if we're talking about a reasonably well researched list like the one we used to have here that was maintained by Dottorent.

What is the exact model number of the unit you are using?

As for the warranty, not much we can do about that if you purchased the unit out of country. This is another reason to avoid MSI. They have shady warranty practices that extend even beyond this particular instance. In this case, I guess I don't really blame them, but this is not the way to support your products.

It's also a good reason for not buying products outside your region. I would suggest that you should probably just buy another motherboard. Not being experienced enough in electronics repair to self identify the problem means you'll likely ruin the board entirely trying to fix it anyhow, and taking it to a repair shop to be fixed would likely cost more than the cost of a new board as well.

Plus, even most professional electronics repair personnel would balk at repairing a motherboard as it's much more complex than, say, a power board from a television. They won't want to be responsible for damaging it any more than I would.

It could any of a number of capacitors on the board, or none of them. It is only a guess from a tech support that has not seen the board, or tested it, nor do they care if you ruin it because they are not going to warranty it anyhow.

Your logic regarding why and how it will power up is fallible. There are plenty of reasons why it might behave that way including the possibility of shorted traces from the 8 pin to the CPU socket or traces. You cannot diagnose the exact failure if it is not clearly visible in the form of bulging, burned or leaking components, without expensive high end repair equipment or at the very least, a manufacturers technician documentation offering exact troubleshooting test procedures. (That probably still call for the use of their testing machines.)


Certainly you can guess, but that's all you'll be doing and it's likely you'll do more damage than good. Again, this isn't an old television power board or some radio mainboard. This is an incredibly complex PCB with traces and solder points that cannot be easily manipulated except with high end machines. You can try, but I've very, very rarely seen anybody repair a modern PC motherboard with any success unless one of the main capacitors was clearly damaged and was designed in such a way that it's solder points were not near any other traces or onboard components. I've fixed an awful lot of power boards by replacing the caps, and I wouldn't try something like this, at all. Even if you consider the board lost anyway, you then lose the investment in the new parts. Not worth it in my eyes.

 

[limsgp]

PSU is Seasonic x-850. It's in the first post.

Locally it costs approx 50~100% more than buying from the US. Its sick that the local markup is ridiculous.