@abigailbardwell,
If it works for a while and then stops, it is probably a heat issue in that an electronic component is failing when it overheats.
cjhsa's suggestion of blowing the dust off is the best one you could do yourself since dust could be preventing a component from cooling like it normally would.
If that doesn't do it, then you can either take a course in TV repair, have someone else repair it, or sell it at your garage sale.