Well, little ACER was sort of working with Mint 17.2 installed but not really well enough for me to return it to my sister in law. Pride in the Linux name is at stake, so I did some more fiddling and followed up some google searches. (Weather is cool and showery so no painting outside, time for some Linuxing)
I am not sure if the Askubuntu page was the one lok1950 was referring to but I did find one entry which seemed to cover the situation nicely.http://askubuntu.com/questions/524894/b ... 3-111-c0wa
is the URL.
After adjusting the appropriate file /etc/modprobe.d , a reboot showed all was well, rapid shutdown and a good clean boot.
Funny thing was at my first attempt I left a letter "d" off and rebooting was no better. How can that simple entry have any effect anyway I was thinking at the time (!)
Another attempt and paying attention this time, I nailed it.
So honour is now restored and ACER can go home.
Thanks for the replies to my query, put me on the right track.