Keyboard problem with DV4-1120US - One keystroke with multiple characters

Guys,

After spending hour reading many thread about HP keyboard problem, I believe mine is a mysterious one.

I broke my LCD with a drop. Now that I replace my LCD, I have a problem with my keyboard. When I type a single letter, it would give multiple characters.

For instance, when I type a letter "h", it displays "nhy6" on notepad. And, when I type any of "nhy6" keys, each of those keys will display "nhy6".

When I type "/" character, it will display "./". And, interestingly, when I press tab key, it will give me the tap space and lit the caps lock light at the same time.

The "fn + num lk" does not seems to work when I press them. In fact, all the "fn + any function key" do not work at all.

I test this notebook with external USB keyboard with no problem at all.

I was wondering if this keyboard problem could be a damage from a drop, or it is something you have seen before.

Please help!
TIA

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Notebook: HP Pavilion DV4-1120US
OS: Windows Vista 64 bit
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What I done so far with no luck;
1. Install newest BIOS from HP site, F.66 REV: A.
2. Remove keyboard driver by uninstall driver from Device Manager.
3. Reseating keyboard ribbon.
4. Press and hold "fn" and the problem key just in case they get stuck.
5. Virus scan.