i found the problem with the azbox premium plus power units. The 82mf, 420v capacitor in the unit is faulty. When it dies, it shorts a circuit that blows the thermal fuse too.
Fix: You must be good at soldering as you will need to remove the heatsink that covers the whole component board.
1. Replace the 82mf, 420v capacitor with a new capacitor of thesame rating. +- 20% tolerance on the capacitance will work but make sure the voltage is greater than or equal to 420V.
2. Replace the thermal fuse. Be careful with soldering the fuse as the heat from the soldering iron might blow the fuse. You might need a 10w soldering iron.
I just repaired my power unit and it is back working like magic.
Enjoy,