Light Fixture Maintenance

I have a Zoomed combo deepdome & a T5HO 39" hood. Sometimes the bulbs go out by themselves before their due date. I'm assuming there's a chance that due to some factors, they won't make it as long as they should. I have done some research on that subject but admittedly need to do more.

However, something that I can't seem to find information on is light fixture maintenance. I know it's something that should probably only be done if you know what you're doing. I've sent one of my fixtures back on warranty since the switch failed. I'm assuming that I can't get a second warranty on the replacement. That's maybe something I should have looked into. Assuming the problem is not the bulbs & I can't get another warranty then there'd be no harm in trying to fix the fixture myself. Has anybody tried doing so?

There shouldn't really be any maintenance required aside from keeping them away from heat and using bulbs with wattages under the rating for the fixture. Is it your T5 that is burning out or is it the bulbs in the combo fixture? I'd certainly try to get a warranty replacement again but maybe relegate it to a portable basking light and replace it with a better fixture. I really like using brooder lamp fixtures because they are cheaper and much sturdier (with higher rated wattage) than the reptile specific ones. This is what I have for my basking lights http://www.theisens.com/indoor-lighting/bayco-brooder-lamp-182-sjeo-x-6-fl-302pdq8