First of all stop trying to turn it or you will damage it more and unplug the battery if you can. My advice is taking to a proper repair shop that has board repairing experience.
Sounds like a Windows software problem. You should get it to a computer technician. One thing you can try is this: Remove your battery and plug in the charger. Turn it on and when you see the windows logo immediately unplug the charger so it powers off. Most of the times if you do this 3-4 times it will go to "Startup Repair" and there you have options to boot in safe mode, do a restore point etc...
Sounds like a keyboard hardware problem me although you said it doesn't happen when you type password and that's strange. Can you boot to Safe Mode and see if it does the same? To boot to safe mode do this: For WinXP, Vista, 7 keep tapping the "F8" key when you power up the computer. For Win8, 8.1, 10 when logging in Windows normall press the "windows key" + "R", type "msconfig" and press enter, go to "Boot" tab, check the "Safe Mode" box at the bottom left of the window and restart your computer. Do the same later and uncheck the box to boot to normall mode. Let me know if it works in safe mode.
Does the daughter board handle the touch fuction of the key or the light only?