Samsung LED Smart TV UA48J6300AKXXA

[valia]

I have a Samsung LED Smart TV UA48J6300AKXXA bought in South Africa which is now in Cuba, country where there is no Samsung service. It was working fine until recently but now when you start reaches the 4th screen tv signal : Antenna or HDMI or Display box . At this point it stops and does not pass the following. No matter which option is chosen. the signal will not enter either Antenna or box or just use it as a monitor.
TV technician tells me that those tv lose their memory programming.
How can memory  be reprogrammed for these tv?
Also they say to me that I must reset main POB. ¿ How to do it?
Others advise to change main board
What you advise me?
¿Where I can find technical manual of this Samsung LED Smart TV UA48J6300AKXXA?
thank you

[wraper]

Have you flashed firmware update and reset the settings from menu? http://www.samsung.com/za/support/model/UA48J6300AKXXA/

[wraper]

BTW starting 2 identical threads is not good at all.

[Simon]

Please don't double post, it is extremely annoying.