The edge connector on the circuit board or the connector coming from the power supply?
Somewhere along the line one of the three "hot" lines(+12, +5, and +3.3 Volts) didn't have enough resistance between it and ground, most likely. If one of the hot lines touched another current would flow because of the voltage difference from the less positive to the more positive one, but the design of the connector puts grounds between those 3.
Unless something in the DVD drive went bad and was drawing too much current, the problem was more likely something about the plug from the power supply.
What was the model number on that DVD drive? (I have a Samsung with problems myself)