Problems with Guage Lighting

[BigRed]

When I bought my '86 Suburban about 2 weeks ago, I noticed that the only guage lights that were working were the ones to the right of the speedo. I could see it barely and nothing else at night. I thought, "no big deal, I don't drive much at night anyway". However, I noticed last night that none of the lights are working anymore. All the guages are working fine, but I can't see them.

I checked the one 5amp fuse that is labeld guage lights and it is not blown. What should I check next? I can't imagine that all the bulbs could have gone out. I'd rather not pull the whole cluster if possible but will if necessary.

Thanks!