Mosfets

[masscrazy]

Whats the reason MOSFETS become 'unsoldered' or burnt?

[aidanjt]

over-volting/heating?

[masscrazy]

over-volting/heating?

Does this (burnt mosfets) make the motherboard useless?

[aidanjt]

mosfets provide power regulation, they go, the power goes.

[masscrazy]

mosfets provide power regulation, they go, the power goes.

Are they easy to repair, once repaired is everything OK? Are there any temp problems after change?

[peterb]

Well, you don't repair the mosfet, you replace it. How easy t hat is depends on how they are soldered in, and your possession of the correct tools and expertise. Provided the failure of the device didn't lead to any other damage, and that the cause of the failure is identified, thjen replacing the device should mean everythging works agai,.... BUT

Why did it fail, what is the background and what are/were the symptoms?

[KowShak]

If the mosfet is burnt it has gotten hot, the chances are that it will have done bad things to the board.

You might be able to desolder the MOSFET and just replace it with another (either the same type or an equivilient type) as long as it hasnt burnt the solder pads or the traces on the board.

[Agent]

One of the most common causes is a short.
Thankfully, if this was the cause they usually burn out before doing any more damage