Tree is half out, fuses ok but there is also a fusible link socket?

I have a 4 ft skinny woodland tree in my kitchen that is 7 years old, from Hobby Lobby. It did not turn on this year but I got the top half functioning using the Light Keeper Pro,. The bottom half does not work, and I noticed there appears to be a fusible link that has a burned out bulb in it. But there are also 2 functional fuses (i tested them) in the plug. Should I give up or keep trying with the lower half? My son thinks that burned out FL bulb means there is no repair that will work. I don't want to waste money if I don't need to…