Upgrade TV by replacing mainboard

Placeholder for article about how to do mainboard replacement.
We can almost easy replace mainboard and get TV upgraded to higher TV model without changing whole TV!

How to

missing (to be updated by someone in future)

Tested on models

UExxC630 -> UExxC650
UExxC6630 -> UExxC679
UExxC6000 -> UExxC6800

References

Here we`re talking about mainboard replacement:

B series

wiki: Upgrade b550 to b650
http://forum.samygo.tv/viewtopic.php?f=3&t=2055&start=10#p18259

C series

http://forum.samygo.tv/viewtopic.php?f=9&t=4517&p=34206#p34206
http://forum.samygo.tv/viewtopic.php?f=15&t=4712#p35213

D series

http://forum.samygo.tv/viewtopic.php?f=20&t=4138#p31582
http://forum.samygo.tv/viewtopic.php?f=20&t=3781&p=29125#p29125