Fluorescent lights from places like Home Depot look good and seem like a real bargain but the ballasts inside don't last. The lights come with a warranty but removing the light and returning it about once a year isn't worth the trouble.
I have several lights in my garage and basement from Home Depot that I installed about 3 years ago. Although I have never had to replace the tubes in them yet all of the ballasts have gone bad in that time.
This instructable will show you how to repair and upgrade cheap fluorescent lights so they will be better than new and will last a long time.

Step 1: Materials Needed

The materials you need are
The new ballast. I have chosen is Advance REL -2P32-SC because I found it cheap on ebay. I am using 2 32watt T8 tubes per fixture. This particular ballast is discontinued, but Advance sells newer type ballasts such as ICN-2P32-N that install the same way.
the main things to look for are voltage (probably 120 volt if this is in your home), number of tubes the ballast will light (probably 2), the type of tubes you will be using (probably T8. I prefer to use T8 because they are more efficient than T12 and T8 will start in cold weather) and the wattage of the tubes you will be using (probably 32 watt)
Small wire nuts.
a pointed sheet metal screw
Screwdriver
1/4" Nut driver
Wire stripper

Step 2: This Is a Common Problem

These ballasts burn out all the time. I got tired of constantly replacing the fixtures, so I decided to replace the ballasts with high quality ones. I have changed more of these ballasts than I can remember, but I have not replaced any of the fluorescent bulbs since I switched to T8.
T8 tubes are more efficient and have a long life.

Step 3: Disassemble the Light Fixture

First of all unplug the light. Then remove the fluorescent tubes and the shade exposing the ballast and wires.

Step 4: Cut Out the Old Ballast

Cut all of the wires close to the ballast. The blue disk you can see in this picture is an MOV I installed to try and protect the old ballast. It didn't help, this ballast died anyway. I will remove it as I install the new ballast

Step 5: Install the New Ballast

Remove the dead ballast and install the new one. The new ballast didn't fit the original mounting hole so I used a pointed sheet metal screw. I didn't need to drill a hole, I just pushed hard as I turned the screw and it worked itself through

Step 6: Connect the Wires

One end of the light may have a wire joining the two sockets together. This wire is usually yellow. All of the wires on this end will need to be joined together. This instant start ballast doesn't need to heat the filaments in the tubes so only one ballast wire (the red one on this ballast) will need to be connected to all of these wires

Step 7: Connect the Socket Wires

On the other end of the fixture one socket is wired with blue wires and the other socket is wired with red wires. Both red socket wires need to be connected to one of the blue ballast wires, and both blue socket wires need to be connected to the remaining blue ballast wire

Step 8: Finish the Wiring

Complete the wiring by connecting the black wires together and white wires together. The replacement ballast doesn't use a ground wire, but there should already be a ground wire attached to the fixture housing from the factory. Tuck all the wires up so they are inside the fixture housing so they won't be pinched when you reinstall the shade

Step 9: Install the Shade

Reinstall the shade, plug in the light and try it out.
The result is you now have a light that is very efficient, it will work in cold weather, the tubes will last a long time and the fixture is dependable.