the L button on my DSL isn't working. I just replaced the top screen (the L button was broken prior to this). I was hoping that disassembling it and putting it back together would fix it, but the L button still doesn't work. My next step is to take the back cover off, and try the little button itself to see if it does work and it's just the plastic L that's broken. If that doesn't work, is there way to actually replace the L button itself?