laptop keyboard sticky key problem help pls.....

[mushtak2917]

i have a sony laptop and have a keyboard issue.... the "[" key is constantly being pressed in. i have had this problem for ages now and have (a year ago) replaced the keyboard (£96!) and have exactly the same problem.
i thought it might be a virus so have even formatted the hard drive; and it's still exactly the same. the funny thing is when you press this key nothing appears on the screen and then suddenly after a while it just goes into it's madness routine. the only way to relieve this sticky key is to press the adjacent "]" (opposite) key and maybe it will stop the stickiness.the sticky key option in control panel is also selected "off"!
when switching the computer "on" it sticks at the reboot stage "forever" with a continual beeping noise until the f8 or ] key is pressed several times; after which the computer continues [[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]
the rest of the boot-up pr[o[c[es[[s.
i can't believe the new keyboard is still at[ [fau[[lt.[[[[]]]]]. any advice would be greatly appreciated. (have to solve this problem as it's a challenge, rather[ than just buy a new laptop!).

p.s i have left the sticky keys above so you can see for your self!
also the left hand shift key pressed in-conjunction with the "p" key does not make the p into an uppercase!... the right hand shift key with this p key works fine! (maybe another clue)[[[[[[[[[[[[[[[[[[[[[[[[[

 

[L33]

Unlikely to fix it but worth a BIOS update if there is one available. Also worth asking does it do it with absolutely nothing else plugged in to the laptop? No USB devices etc?
If so, the fact that it does it at boot (ruling out any software) and you've replaced the keyboard points at it being some sort of hardware fault on the motherboard unfortunately. You could try cleaning the keyboard ribbon connector on the motherboard (remove keyboard ribbon, apply a little isopropyl alcohol to a cotton tip and gently wipe the connector terminals). If you know anyone with electronics experience, have them check (where possible) the path from the keyboard connector back to the IO/southbridge chip. The chances are it could be a failed SMD resistor or something causing a transistor to stick open when that 'branch' of keys is triggered.

 

[mushtak2917]

L33... thanks for the suggestion. just to conf[irm there [are no other usb devices plugged in.
i was thinking of the motherboard myself. but would find it daunting meddling at SMD component level to trace this fault. if i take it to any so called experts they will just dismiss it saying i need another [[m[othe[r[ [[board!
which will be un-economical....... do u [really think a BIOS update will fix this problem?... and how so?

 

[L33]

I'd very much doubt a BIOS update will solve it unfortunately, but with nothing to lose it would be worth a try if there is one available.

 

[mushtak2917]

do u [know any reliable firms that c[an [possib[[ly diag[nos[e[ [t[he [pro[[bl[em[[[[?[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[]]
i live in London.