Philips 39PFL3208k/12 keeps rebooting help!!

[Ere]

Hi
model of the set: 39PFL3208K/12
MAIN-BOARD: 715g5713-m0e-000-005x
The set keeps rebooting endlessly, this after Philips logo.
tried to upgrade via usb stick, formatted the USB Drive with FAT32 system and put in the autorun.upg download from the official website for this, unplug the set and plug it again but the tv doesn't detect the USB Stick, also tried this way with pressing Ok button from remote control and also using other buttons like arrow down as many users suggest, no success.

no need the dump of the main nor flash u4051..

thanks for helping