Heat is the greatest enemy of your lamp performance. Try to keep room temperatures around 66° Fahrenheit. Salons are not beaches! Remind your customers that heat does not contribute to the tanning process.
Flickering may indicate a need for new starters. Starters give an extra burst of current upon activation, reducing wear. Note that used lamps will start more readily than new ones.
It is important to clean each unit thoroughly at least once a month to maintain maximum UV output.
Be sure that the sockets are clean and that the lamps fit snugly. If sockets have loose contacts or worn springs, replace them. Worn sockets can cause premature darkening of lamps, arcing, and can shorten lamp life.
Check acrylics for cracks and yellowing. An old shield can block up to 70% of UVB rays.