We have a Signal generator from Hittite (Model No:T2100; S.No:000534). It was on for a few minutes and then it went off after giving a sound. Then, it couldn' t be turned on again. The indicator on its power supply is not glowing. There seems to be some problem with the power supply adaptor of the hittite. What might have gone wrong? How can we troubleshoot the problem? Please help us in this regard.