Most likely the problem is with RTD2523. The board is BENQ 48.L1G01.A02. The power supply is providing 4.97V and 3.28V in standby mode and 4.93 and 3.26V in "on" mode. I checked and the chip should work with voltage greater than 3V, so 3.26V should be fine. Now I have RTD2523, will write later what happened.