Windows 7 Screen auto-scrolls up on my Acer Aspire 5742G notebook

[rameshiyer]

I have been using my Acer Aspire 5742G notebook for over 2 years now. Recently, I noticed a peculiar and very irritating issue. Rather two of them. First, the screen auto-scrolls abruptly and randomly (in no particular program, be it MS-Word / Excel or any browser). Also, when I type anything, again in any program, the cursor jumps to the beginning of the line I am typing on.

Have got 64-bit Windows 7 & SP1 reinstalled using the recovery discs, and also took the notebook to the Acer Service Centre but since this is intermittent and happens at random, couldn't simulate the same while at the Centre for about an hour.

Would be grateful if experts / IT savvy folks can help me sort these irritating issues, as it's becoming very difficult using the notebook.

Also, have got the keyboard cleaned, and also have got latest drivers installed for the Synaptics touchpad which haven't helped. Doesn't seem to be a Windows related issue, as when I start / restart the notebook, and it shows the BIOS password screen, it shows some characters being typed out into the password field automatically. Similarly, after I use backspace and remove all characters and enter the correct one, and Windows shows the user-password screen, again some characters get typed automatically till the end of the password field. Again I have to delete them and enter the right one.

 

[Josephur]

Since it happens in the BIOS I seriously doubt its a driver issue, I'm guessing your keyboard is shot. It's common for the membranes to wear out and if the keyboard has been abused in any way (drink spill anyone) it can exhibit this behaviour.

I'm seeing your keyboard is pretty darn cheap on eBay and its something you could probably replace yourself:
http://www.ebay.com/sch/i.html?_trk...Acer+Aspire+5742G+keyboard&_sacat=0&_from=R40

 

[rameshiyer]

Since it happens in the BIOS I seriously doubt its a driver issue, I'm guessing your keyboard is shot. It's common for the membranes to wear out and if the keyboard has been abused in any way (drink spill anyone) it can exhibit this behaviour.

I'm seeing your keyboard is pretty darn cheap on eBay and its something you could probably replace yourself:
http://www.ebay.com/sch/i.html?_trksid=p2050601.m570.l1313.TR0.TRC0.XAcer Aspire 5742G keyboard&_nkw=Acer Aspire 5742G keyboard&_sacat=0&_from=R40

Thanks @Josephur for your suggestion. Yes, since the strange auto-input of characters happens in the BIOS password screen, I too suspected it must be something to do with some hardware component. But, since it happens intermittently, and difficult to simulate, I am somehow managing with an external mouse & keyboard for now. And no, the laptop stays at home and is rarely carried outside, nor do I ever have any eats / drinks anywhere near it. So, spillage or foodstuff (crumbs?) lodged in the KB is ruled out, as I noticed nothing of the sort while cleaning it with the cleaning kit with me.
The laptop is covered under extended warranty hence I can give it to an Acer ASP to fix any hardware issue (and avoid incurring an expense, however small!), but trouble is that they take ages to sort out even issues which can be fixed in an hour, or at most one day.