how can i fix my satellite receiver (lemon 07ci) ?

My satellite receiver begun working very slowwwwwwwwly until it stopped working at all.If i connect it and disconnect it from the mains it stays in "boot" forever. I tried downloading the firmware i got from the internet (from Lemonworld) to the receiver using a rs232 cable,and it didn´t cure the problem.So, is there anything i can do to have it working again?
thank you for your suggestions