Throw a try catch block on this line
SqlDataReader dr = cmd1.ExecuteReader();
and a break point and step throguh and see if it is throwing an error and you can see what that error is.
Minimal current consumption.
A laptop or cell phone power supply will draw a little because of the AC/DC circuit inside.
Newer TVs also will draw small current because there is a small cicuit powered on waiting for you to turn on and control the other sections of the tv.
A toaster may or may...