I have the same problem I tried 2 different programming cables and 2 different serial to usb adapters. I have already factory reset my remote too so I am out of a remote currently.

I am not sure if my cables are correct but they are said to be for mx 850. Here are the ones I bought:

According to the "correct pinout" both of these are them...

[Link: ebay.com]

[Link: ebay.com]

I always receive "FAIL" on my LCD. Please help!