7805 regulates to 5 volts, the regulator on board requires about 2 volts above 5 volts to give 5 volts. verify that the 7805 is actually putting out 5 volts and attach it to the 5v pins bypassing the regulator
even then you are still going to have problems (not even counting that 36 volts is beyond the capibilities of the part)
(vin-vout)*current = watts
(36-5) * 0.1 = 3.1 watts
50 degrees per watt * 3.1 watts + ambient temperature (lets say 27) = 182 degrees c (359f) is quite a bit higher than the absolute max of 125 just at a 100mA load