It's possible the butane lighters are clogged. My Blazer stopped lighting earlier this summer and I had to take the whole thing apart and use canned air to clean everything. Since then it's worked perfectly.
Your best bet is to get a small screwdriver and start tearing things apart. Take photos or write down instructions while you're doing it so you can be sure to put everything back. Long story short, at some point you'll find a long tube that allows the gas to travel from the reservoir to the igniter, that's probably what's clogged.