9630 Keyboard/Buttons not working; hard resets and multiple reloads of OS did not correct

Question

My BlackBerry 9630 Tour is a little more than a year old. Yesterday the keyboard, trackball, and all buttons stopped working while I was typing out an email. I could not power off the Blackberry without removing the battery for a hard reset. Unfortunately, even after many hard resets, the problem persisted, so I went to the forums for help and tried everything that seemed relevant (multiple times) with no success.
After reviewing a number of tech support posts, this problem does not appear to be unique to any given model of BB and contact with liquids is cited as a common but not the only cause for this condition.
I was outside on a very hot and humid day when the malfunction occurred so it is possible some perspiration may have come into contact with the keypad, convenience buttons, or trackball and caused the lockup.
I'm looking for someone with more smarts than me to help me troubleshoot, identify the actual problem, and identify the proper corrective actions. See below for a synopsis of my actions taken, with the exception of taking it to the shop for repair/replacement.
The corrective actions listed on the forums and blogs are varied but essentially fall into two primary solutions:
1. If moisture is suspected to be the issue, let the BB dry out overnight
    a. Pull the battery, naturally air dry or use a blow dryer, let it sit unplugged with no battery for at least 12 hours 
    b. If this doesn't immediately work, try a clean install of the OS (see below)
    c. If this doesn't work, take to the shop and they'll either replace the keyboard and/or trackball or replace entire unit
2. If moisture is not suspected to be a factor then perform a backup followed by a clean install of OS
     a. Backup your files using Desktop Manager Backup and Restore
     b. Do a clean reinstall OS using Desktop Manager Application Loader
         i. The OS installation process is dicey  and takes a little patience and focus-- you have to wait for the Desktop Manager to properly recognize the device before it can proceed on some of the steps and it may take several iterations to get completely through the process and get the "successful installation" message.
         ii. Further, you may need to keep the battery removed during the initial steps in the process and only insert it when the process gets to the point of actually trying to copy files into the BB memory
            * The BB LCD will display an icon that looks like a battery with a slash through it letting you know the process cannot proceed until a battery is inserted and the Desktop Manager Application Loader will also give you an error indicating it cannot find the device.
            * After inserting the battery, it will take a few seconds or more for the computer to recognize the USB device and for Desktop Manager to respond with the BB password pop-up window.
            * After typing in your BB password, the installation should continue.
    c. If you can get the OS successfully reloaded and your keyboard/trackball/buttons work -- great -- now restore your files and settings using Desktop Manager Backup and Restore and get on with your life.
    d. If this does NOT work after multiple successful clean OS installations apparently you are completely hosed; the only other option is to get it to the shop for repair or replacement.
1.. Does anyone have a troubleshooting procedures that will identify whether moisture is the root cause or not?
2. Is there another corrective procedure that's been missed?

Answer 1

Took  BB to Sprint Store and technician took it apart, saw no evidence of moisture or any other damage, and concluded that the keyboard had failed. Not an uncommon occurance.
Also, he told me you cannot simply replace the keyboard, it is integral to the systemboard, so you need to replace the entire device.
He did commend the troubleshooting approach used prior to going to the store -- most folks won't take the time to do even basic troubleshooting (like taking out the battery), they just go to the store and say "fix it please". He confirmed that the steps outlined in the initial post were correct and did not have any other solutions.
Take away:
If you want to do some troubleshooting yourself to check for moisture, the process was pretty straightforward. After watching the technician, most folks with a little technical or mechanical aptitude should be able to manage the dismantling process. You just need a small phillips head screwdriver and a little patience. Good lighting and a magnifying glass or reading glasses also help!