Samsung QE49Q6FNAL short circuit

[kristofl]

Hi,
I have a Samsung model QE49Q6FNAL, type number: QE49Q6FNA, which suddenly shut down while playing.
Now I opened the TV and heard the power supply beeping at a high frequency. If I unplug all cables from the motherboard (BN41-02636), except the power supply to the motherboard (BN41-02636), the problem remains.
Now it happens, when I pull the power supply from the motherboard, the backlight comes on. The squeaking noise from the power supply is also gone.
So I suspect a short circuit on the motherboard? Because when I plug the power supply cable back into the motherboard, the backlight goes off again and the beeping starts.
I can't immediately find anything that gets hot, except the CPU itself under the cooling block.
Stb_voltage is stated on the power supply as 11.8V.
When I measure this with the multimeter it is 12.8v.
When I plug in the motherboard, the backlight turns off and the standby voltage remains 12.8v
Are there things I can still try myself?

Thanks in advance for the help

[KYBOSH]

Post pics of the entirety of the back of the TV with the panel off so we can see what we are dealing with.
Closeup/High quality pics of each of the major boards will also be helpful.
Video of the TV acting offensively (with sound highlighting its origin) would be very helpful too.