after having plugged the power-adapter with inverted supplies (19.2V +/- swapped) into the ASUS U5F notebook of my wife (you'll understand the severity of the problem), it has burnt a little bit and since then the USB (maybe the 5V supply) seems to not work correctly anymore (the rest seems to be ok).

To investigate the problem until now I found out the following:

• the schematics of the mainboard are not available
• the device seems similar to the Asus U5A (no schematics available either)
• at least one component has burnt (as pictured below)
• I'm unable to identify what this component is doing exactly, so I can't replace it
• the components is of probably packaged using "SOT-223-4"
• the marking code is 8C609 (I could read it before cleaning the section, now there is only "8C6" left)
• I suppose it is a LDO-regulator, but I don't know the exact reference