hi mate
i had the same problem with my dm900 clone box.the red light was constant on, i have tried every method but no luck.the problem was solved by using "OptiFlasher Pro [DMips EDition]" from yassinov .i had the keys for the opti flasher from yassinov.
i follow all the steps by using the keys for opti flasher pro,then my box come back live and red light went off since then its working fine .yassinov is very helpful person. i hope this might help you.