Landscape lighting bulbs have to fight the elements. There are so many elements that can cause them to lose their brightness and fail. You can install a new MR-16 light bulb and watch it fail in a matter of days. What did you do wrong? You installed it with your own bare hands and it still failed. Well, it failed because you probably did not know that this type of bulb is susceptible to the oil on human hands. So when you changed it with your own bare hands the oils on your fingers caused it to overheat and burn out and now you are changing it again.
Things You'll Need
Turn off the transformer for the lighting system you are working on.
Use a Phillips screwdriver to unscrew the housing and lift the glass lens out of the housing and set aside. In most cases you will find the housing screws on the face of the light. On many newer light fixtures, the housings unscrew without the use of a screwdriver.
Put on some rubber gloves or put a plastic bag over your hand because most landscape lights use halogen bulbs and these require special handling. Remove the old bulb. Handle the new bulb by touching the rim or reflector and not the actual bulb.
Check the old bulb. Look at the prongs for corrosion. If it is heavily corroded this might be the cause of the problem. There may be a leak in the watertight seal and you may have to replace the whole fixture.
Place the two prongs on the bottom of the bulb into the two holes in the light fixture. Do this carefully while holding the reflector of the new bulb.
Screw the housing back on. Clean the lens and check the wire connectors for corrosion. Reposition the light. This is a good time to check all the lights in the system and perform any preventive maintenance on the system.
Never touch the glass of any landscape lights with your bare hands. Most of them are halogen lights which burn very bright. This factor means any oil on the glass will cause the light bulb to overheat and burn out.