Hi, I accidently reversed polarity on Asus X301. Now the laptop turns on with charger connected and battery inserted, but after several seconds it shuts down by itself, I power it on again and shits down faster, and the third time it won't power on. After some time it can be powered on for several seconds. During this time windows starts booting and everything seems normal, until it loses power and shuts down.
Is the laptop damaged, the battery or the charger?

When I've seen this, the motherboard is usually toasted somewhere. The battery and charger are of course suspect but odds are motherboard first.

I basically agree with "rroffitt", the system board is damaged and the likelihood of an inexpensive repair is about zip (it would require OEM hardware, most likely all the circuitry). The best news is that you may be able to xfer the HD to another (new?) machine. If not, with a USB drive adapter you can connect the existing HD with another on another machine, preferably a desktop, for a full backup. The actual eventual target would preferably be another compatible ASUS but that isn't necessarily always required. You might also browse the net for another ASUS X301; a good used one may be w/in your reach financially. Beyond this, the variables are too many for an easier fix. The power adapter may be reused but the batt. is at best, unreliable.

From official service told me that the motherboard is damaged. Thanks for your support