This is not a problem but may be due to the surge current that occurs due to the charging of the power supply Filter capacitors. This might be made less with some silicone sealant. Best to have a Technician look at it as it could also mean a too high of current draw due to aged and defective Chinese Capacitors- yes the have infiltrated this business too and are the result of many a failures including flat panel display TV's and computer monitors.