I remember here was exact same problem. But i do not remember the solution for it, must think and search forum.
One question - did you disable watchdog in ServiceMenu ? if not - do that. It is enough time until TV reboots...
If you do not know how, read here.
UA55c7000
Re: UA55c7000
LE40B653T5W,UE40D6750,UE65Q8C
Have questions? Read SamyGO Wiki, Search on forum first!
FFB (v0.8), FFB for CI+ . Get root on: C series, D series, E series, F series, H series. rooting K series, exeDSP/exeTV patches[C/D/E/F/H]
DO NOT EVER INSTALL FIRMWARE UPGRADE
Have questions? Read SamyGO Wiki, Search on forum first!
FFB (v0.8), FFB for CI+ . Get root on: C series, D series, E series, F series, H series. rooting K series, exeDSP/exeTV patches[C/D/E/F/H]
DO NOT EVER INSTALL FIRMWARE UPGRADE