I've been having a similar issue with my softmodded 1.6 box. The video signal temporarily drops like yours, but way less frequently. Around once or twice per day, lasting about a second or so.
After a bit of research, this 2013 thread helped me figure out the cause.
If this is the same issue, then it's to do with the power supply. Certain XBox PSUs are built and tested with only SD resolutions in mind, and become sensitive to otherwise normal power fluctuations when run in 480p/720p/1080i via component cable. The fluctuations in question can be caused by stuff like a washing machine spinning up, a fridge's compressor activating, or simply turning on a light somewhere else in the house.
Mousxaros, did you ever test with an analog/scart cable? If you did and the issue persisted, then it's either a different problem or perhaps that your box's PSU is on the way out. You could try taking the box to a friend's house and testing it there to see if it makes any difference. If it's the same issue I'm having, then the only solutions are likely to be A. Run in SD or B. Get your box's PSU replaced.
Good luck getting it fixed!
El cable por componentes también debe ser de buena calidad. Con un adaptador HDMI de bitfunx, el que lleva la carcasa metálica, he encontrado que funciona bastante mejor, casi no lo hace y puedo jugar partidas largas sin que lo haga. Dados los precios de los cables por componentes, es una buena alternativa.