Toshiba notebook pa3299u power problem. I tested ith multi meter my power supply and it work fine. The problem si when I turn on the power then no led. not noise, nothing happen. I would like to know if somebody know which piece broke often in that case please?

Power supplies have been known to go bad but still test good. Reason being is your more than likely only testing the output voltage and not the output amps. The amps are the most important thing, you can have your voltage but the psu may not be releasing enough amps to power the processor.

Also depending on the age of the laptop you may have a fried processor which will cause a similar senario.

Or you may have simply had someone kick the power cord while it was in the laptop and caused the dc input jack to break it's solder connections, which is usually the case i see in my shop.