Everytime I purchase a receiver which decodes over the internet, it stops decoding after a month.

I am a n00b in this and I would like some help/instructions on how can I make them work again either by erasing their flash and using other flashes of other receivers, I don't know.

The V3000 has an RS-232 to RJ45 dongle which decodes
The Dreamsat 6000 has direct RJ45 connection.

Appreciate any help I can get.