Basic Inverted Gain Clone

Hello, i am a first time di your-selfer building an inverted gain clone. I finished the psu and one channel and decided to try it out so as not to double up on my mistakes on the second one.The psu is putting out 37 vdc each rail.When i powed up the LM3875t chips No1 terminal heated up and broke off,also leaving the backing plate to the chip heat affected.Could any-body give me some advice on how to rectify the problem please.

Thanks,Clive