FOXCONN G33M02 Motherboard Short

[Wilksey]

Hi Guys,

I have a Dell Inspiron 530, it's about 4 years old, got a dual core processor, the pc suddenly died the other day with no warning, I have diagnosed the 4 pin ATX processor power connector that stops the system running.

Upon further investigation I took everything off (including CPU) and found there was a short between the 12V and 0V on the 4 pin ATX (not on the 20 Pin ATX), which is shunting the PSU.

Dell being "special", only parts which fit are Dell only, and are obsolete. Yay!

I have checked for obvious signs of burning or anything slightly brown, nothing jumps out at me, I have the motherboard out under the microscope to see if I can see anything, still nothing.

What is the likely hood that replacing the 1500uF caps around that power supply will resurrect it? I don't have any rated to that so I would have to buy some, normally I would just replace the thing, but they are not easy to get hold of.

Unless anybody else has any other suggestions?

None of the caps have their tops raised or are leaking, but that's the only thing I can think that would short the 12v to 0v, there are about 6/8 mosfets around the PSU circuit also.

Thanks!

Wilksey

 

[Diver300]

I would try putting as much current as you can continuously source into the 12 V connector. You may then be able to use a sensitive voltmeter to detect the voltage drop across the board and work out where that is smallest, which is probably where the short it. The circuit may also get warm at the point where it is shorted.

In my experience, electrolytic capacitors go open circuit when they fail.

 

[tunedwolf]

I suspect it's either a faulty switcher ic, or a farked ceramic decoupler cap. Either a Milliohm meter or possibly an ESR meter would likely find the short for ya, or get you very close to it at least. Or as Diver has suggested, try the "burndown" method

 

[Sceadwian]

Dell being "special", only parts which fit are Dell only, and are obsolete. Yay!

What are you talking about? All the Dell machines I've ever owned use 100% standardized components.

If something failed dead short like that there's not a lot of hope of repairing it. It'll probably cost more in time and effort than it would to buy a replacement motherboard.

 

[picbits]

What are you talking about? All the Dell machines I've ever owned use 100% standardized components.

Some of the older Dells used to use a non-standard pinout on their ATX connector - unfortunately people will always remember this and assume that all Dells are the same.

 

[Wilksey]

Ok, so it's not likely to be the caps then is what I can gather from peoples responses?
I don't know if caps go open or short circuit when blown.

Sceadwian, what I am talking about is the Dell I am talking about in particular does not use a standard motherboard, it uses a proprietary one designed by Foxconn as part of their G33 range specifically for Dell. The G33M02, the ATX connectors are all standard etc, but the motherboard isn't, I could replace it with another similar micro ATX but would have to start cutting the case as the Dell case wont accept any other board supplied backplanes, plus the O/S would be defunct as the O/S certifies through the BIOS, to check it is a genuine Dell BIOS. All of which would be less painful to either:
1) Fix it! Which is why I am asking on here.
2) Find a replacement, not easy since they are obsolete, got a few companies to try.
3) Replace the case / base unit and save some of the components, but I may as well get a new unit for the sake of £180, plus £50 for a Windows License.

If someone had said "yes, I have had this before, just replace the 3 or 4 1500uF capacitors and it will work fine" then I would have attempted to fix it myself, as it seems they are the most popular component in the failure of board power supplies. I'm not going to "hack" it to try and make it work, if it needs a new board then it needs a new board, I may well get a new board and keep the old one to experiment with fixing it.

I appreciate all of the responses, I do not have the time to fault find that deeply, so as mentioned I may put it to one side for a later project.

I will say that all of the Dell machines I have owned, which have been a few, they all use proprietary motherboards (usually popular models of existing boards with a slight change), some other mobo's have the same backplane, but this particular one I haven't found one that has the same backplane, other components such as PSU, Drives, CPU, Memory, Graphics boards are all standardised components.