I had my Dell inspiron, the 2-in-1 tablet/laptop model for JUST over a year until it started having issues with the battery... It would be very unreliable and sometimes not recognize the charger, saying plugged in, but not charging. I took it to a repair shop and they tested a different charger, different power dock, and differnt battery and nothing work. The conclusion was that it is a motherboard failure. I am shocked as I've had this just over a year.. so, just out of warranty! Very dispapointed, paid $1000 last year for this.... Now I have to buy a new computer, most definitely NOT a dell.
The board is essentially everything inside the system -- any part of which can fail at any time. If you replace the system, be sure you get a 3-year warranty no matter what you buy -- parts do fail, and the way current systems are designed, just about everything is part of the mainboard, so repairs are expensive when something on the board fails.
The failure rate for all notebooks is about the same, regardless of manufacturer's name on the outside - not surprising, as they're all built with components from the same small pool of manufacturers, by contractors comprising a small pool of ODMs.