How to test fluorescent bulbs<br>Look for dark areas at the base of the bulb. When bulbs age and have been used for a long time, brown spots will appear. If darkness begins to form at the ends of the tube, the bulb may be near its end.
Brown spots on the bulb will indicate that the bulb has is nowhere near its end.
( z1 indicate :ARG0 ( z2 spot :ARG1-of ( z3 brown ) :location ( z4 bulb ) ) :ARG1 ( z5 near :polarity - :ARG1 z4 :ARG2 ( z6 end :ARG1 z4 ) ) )