Motherboard unresponsive, need advice on parts

  TraineeAngel 21:37 16 Jun 2013


I was working on my pc this afternoon when it suddenly shut down. I was just browsing the web so not doing anything that could stress the CPU or PSU.

I opened it up and stripped it down. I cleared the CMOS but it still refuses to turn on. I am a former electronics engineer and want some guidance as to the offending component. Unfortunately I am short of cash so I cannot even get a second hand replacement. This is the second motherboard that seems to exhibit the same symptom.

There is an indicator light on the MB but it (mb) refuses to power up as normal. I have tested the PSU and other peripherals and they are fine. In short (and this is what is so frustrating) when I pull out the what I believe is the 12V (square connector) it will power up fine but of course will not do anything as the 12V connector is disconnected? Am I making sense?

It must be just one component that if I service can breath new life into the mb. It is 5 years old intel board that came in my Vostro 410. Any help will be appreciated as I need this pc up and running again. Like I said I have had the same thing happen to another mb recently in another machine.

  rdave13 23:21 16 Jun 2013

How have you checked the PSU? Under no load the 12v rail may read ok. Supplying the mobo will be a different matter. Hopefully it's the PSU dying and not the motherboard.

  onthelimit1 15:05 17 Jun 2013

As it powers up with that lead disconnected, it shouts PSU to me. They don't necessarily fail completely - with the 12v plug in (CPU supply, I believe) it may be trying to take more power than the failing PSU can provide. Plugging another one in is an easy way to prove or eliminate the the existing supply as faulty.

If the problem is the mobo, then I'd suggest that you've had it. Non serviceable item IMHO.

  TraineeAngel 15:28 17 Jun 2013

Thanks for the replies. I did try another working PSU and it was no different... just seems strange that this is the second motherboard to break down like this in a short space of time :-(

I have "serviced" a mobo before without too much difficulty despite the size of the solder blobs and it was a success.

  onthelimit1 14:02 18 Jun 2013

'I have "serviced" a mobo before without too much difficulty despite the size of the solder blobs and it was a success.'

Blimey, you have my admiration. I can cope with power sockets on laptops, but nothing much smaller. Don't know how to identify the faulty chip though.

  TraineeAngel 16:29 25 Jun 2013

I have had a closer look at the dead motherboard and discovered a faulty power regulator D452. It has shorted so I have ordered some. It is just if this is the only faulty component then I can repair it and use the mobo again :-)

Others who have experienced my problem may want to take note of this.

@Onthelimit I have been trained in dealing with basic faults. But had it been a small component I don't think I could have dealt with it ;-)

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

Honor 9 Lite review

How Social Media has Propelled Political Graphic Design and Art in the Last Decade

The best kids apps for iPhone & iPad 2018

HomePod d’Apple : date de sortie, prix et fiche technique