Always read and save your current corrupted firmware before overwriting it.
Remove the back cover to access the TP.S506.PB801 motherboard.
If the TV still won't boot, you may need to check the power supply voltages or replace the board entirely, which is available on Amazon or eBay. Download S506 PB801 HISENSE LTN40D50EU Backup Dump rar
You can find the TP.S506.PB801 Backup Dump on technician forums like HowToFiXiT.gr .
Before downloading, verify that your TV's internal hardware matches these specs. Using the wrong firmware can permanently "brick" your motherboard. Hisense LTN40D50EU / LTDN40D50EU Always read and save your current corrupted firmware
Look for an 8-pin chip (typically a 25Q64 or 25Q32).
Plug it into the TV's USB port (use a USB 2.0 white port if available). You can find the TP
For official software updates (if your TV still boots), check the Hisense USA Support page by entering your serial number. 3. Installation Guide (SPI Programming)