This laptop charger was advertised as Acer compatible, but really isn't. First of all, I believed I'd bought a Liteon PA 1650 charger, then when it arrived I realised it was only Liteon 'compatible'. In order to make it work, my laptop has to be on a firm surface with the plug in the back of the computer 'just so'. Then, as long as no one touches it, and there is a prevailing wind, it should work. This isn't really up to the job, but returning it seemed such a faff that I'm afraid I'm just putting up with it.