Samsung ue49mu6225k intermitent working

[Carlcox89]

Hello all,
I have a friend's Samsung UE49MU6225K with bn41-02568b that is working intermittently. ie. sometimes i have standby light and can power on, sometimes no standby light and cannot turn on.
I have checked that disconnecting main board BN-41 from the power supply, the voltages are good and panel light comes on. So i guess it's the flash corruption bug present in this MU models, right ? However, i cant understand how it is able to fix it by itself sometimes?!
After some fiddling with a bus pirate i was able to dump the flash.
Could someone tell me if it's indeed flash corruption on the W25Q40 IC ?

[lotas]

Your dump is in perfect order, working.

[Carlcox89]

What else could cause this behaviour ?

[lotas]

Check the power supply when the standby LED is off, the dc-dc converters on the motherboard, the contacts of the connecting cable between the motherboard and the power supply, replace with a new spi flash 25q40...

[Carlcox89]

Check the power supply when the standby LED is off, the dc-dc converters on the motherboard, the contacts of the connecting cable between the motherboard and the power supply, replace with a new spi flash 25q40...

I have checked the power supply with the cable to mainboard disconnected and :
- found that the JP821 (is floating... and shouldnt be)
- the panel lights up
So i ordered a CH341A and tried to reflash with my original dump. It flashed successfuly but I cant write the QE and CMP bits (even after doing the mod on the WP and HOLD pins, pulling them through a 4.7k resistor to vcc, instead of being direct to vcc)
Reconnected all the cables and now (after flashing) the JP821 reads 12.8V when standby led is on... and the TV powers on and the JP821 still reads 12.8V.
Why was the JP821 floating (even without connection to mainboard) ? and why does it read 12.8V when on standby and also when tv is on ? (shouldnt it read ~7.5V when standby and ~11.8 [12.8V] when on, according to the power supply label ?)
Next steps ?