03-08-2018 09:37 AM
I have an A740 all-in-one which has given good services until recently when the cursor started jumping all over the place.
This has got steadily worse though it will do some things like playing video OK.
Lenovo disgnostics suggest that there are no hardware problems and I have tried restoring from a backup to no avail.
Because I suspected that the problem might be related to a recent Windows 10 update, I tried a clean install of W10 but the problem was occuring during th einstalltion process.
I read a post which suggested a BIOS upgrade but I can't immediately see where to get the relevant update - I tried one which stated that it was not suitable on installation..
03-09-2018 10:06 PM
Further to initial post, I contacted Lenovo support who supplied a link to update the BIOS - however, it was the same BIOS as that identified elsewhere on this forum and basially won't install.
Support also suggested unistalling the touchscreen driver which actually solved the immediate problem - though, by 'trial and error' (mainly error), I found that it best to 'disable' rather than unistall the driver, which will only be reloaded again at startup.
Although Lenovo diagnostics suggest no hardware problem, detailed examination of the tests doesn't really indicate that the touchscreen is specifically tested.
So that leaves me with a working A740 but no touchscreen which I can kind-of live with.
My suspicion is that a recent Windows 10 update was the primary cause of this problem and I await further information on how to restore functionality of the touchscreen.