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How old is this set?
10 blinks is more commonly the SS, SC or A board...
Power down, disconnect the SS and SC boards from the power supply and repower... If still 10 blinks the problem is the A board...
As you have already replaced this by the sounds (the A board is often described as the main board) then the problem is more likely the SS and SC boards, to identify which you will need a meter...
Then one or both of these boards are the problem not the A board... You need to monitor the supply rails as you power up the TV with first the SS board connected then the SC, one of these will cause the rail to drop (and sometimes both of them)
As I say, I have seen one or the other or even both... Only way to be sure is to measure the rails..
If you are a component level technician the boards can be repaired... Don't forget to rate my help, it is how the site rewards me for my time and costs you nothing to do... I will hold the question open so you can come back anytime to discuss this..