M1330 Windows 7 Home Premium 32 bit. 4GB RAM, Corsair XTi 240GB SSD, BIOS A14, Intel Core 2 Duo T9500 @ 2.6 Ghz. Nvidia 8400M GS integral GPU with Copper shim mod.
This started when I had to remove the original NK750 keyboard to replace the LED/LCD screen.
Initially, when I re-booted, the following keys were inoperative:
B, N, /, spacebar, rightALT, left arrow, down arrow, right arrow.
Later, when the different keyboards were tried, the following additional keys became inoperative:
ZXCVM,.
Presently the entire bottom row of keys, z through m, ,./ spacebar, rightAlt, rightCtrl, left arrow, right arrow, down arrow, enter keys are not working. I am thinking that this is a hardware problem and the motherboard will need to be replaced to fix a bad connection where the keyboard ribbon mates with the fold down latch.
The following troubleshooting efforts have been tried but the laptop keyboard problem persists:
A new generic un-branded keyboard was purchased, but it produced the same dead key results as my original keyboard.
A new Dell JM629 Black keyboard was purchased, but it produced the same exact dead key results as my original NK750 and the generic un-branded keyboard.
An external USB keyboard functions normally.
On screen keyboard functions normally.
Ease of access center sticky keys, toggle keys, filter keys, shortcuts were verified as off/unchecked.
Keyboard test using the Dell Utilities disc verified that the keys in my above list are not working.
Device manager shows “This device is working properly.”
OS upgraded from Vista Home Premium 32 bit to Windows 7 Home Premium 32 bit.
Keyboard driver updated to 6.1.7601.17514, no change.
Uninstalling the keyboard and letting Windows reinstall the keyboard, no change.
So, 3 keyboards exhibit the same dead keys.
Looking at the keyboard ribbon attach point through an 8x magnifying glass, I see no obvious bent pins or foreign objects.
I think I have eliminated all software issues, so my problem is probably hardware related. Is there anything else to try before ordering a new motherboard?