The project started with the need to diagnose and attempt the repair of a Hisense television that had stopped powering on. The 55-inch model presented a specific failure symptom: the standby LED blinked three times before settling into a solid red state. The unit showed no image, no sound, and no backlight.
The maker first accessed the internal electronics by removing the rear chassis screws. Measurements were taken on the mainboard and T-Con board using a digital multimeter. The internal components included a combined power supply and mainboard labeled RSAG7.820.10637/ROH, and a T-Con board labeled RSAG7.820.11117/ROH. During diagnosis, the maker also isolated the panel ribbon cables. The repair sequence involved disassembling the screen frame to expose the LED backlight strips.
One backlight LED was discovered to have a burn mark and was damaged. The maker bridged this dead LED. Following this repair, a replacement T-Con board was installed and connected. The maker checked output voltages at the backlight connector, confirming the test involved 280 V DC. Despite these efforts, even after replacing the T-Con and bypassing the damaged LED, the TV still displayed the three-blink failure pattern.
The maker ultimately decided the fault was likely either a corrupted software issue or an unrepairable display panel. The maker then stripped the television of its functional parts, salvaging components such as the mainboard, ribbon cables, and other T-Con boards.
Project by PhilStudio. Watch it on their YouTube channel: