This is a high-level repair. It requires opening the TV, desoldering chips, or using ISP (In-System Programming) headers. If you are looking for a standard update, you should first check the official Hisense Support page.
Unplug the TV and hold the power button for 30 seconds to drain residual power. Download Hisense LCD40V86P RSAG7 820 1856 Dump rar
No response to remote or physical buttons despite a standby light. Infinite reboot loops. Risks and Considerations This is a high-level repair
The request for "Download Hisense LCD40V86P RSAG7 820 1856 Dump rar" refers to a technical used by technicians to repair the main board (RSAG7.820.1856) of a Hisense LCD40V86P Unplug the TV and hold the power button
Files found in .rar format on forums are community-contributed. There is no "official review" for these files; their "quality" is determined by whether the TV boots after flashing.
Visit the Hisense Firmware Support site and enter your serial number to see if a USB-loadable recovery file is available.
If the TV still powers on, you can try accessing the service menu (typically Menu + 1147 or Menu + 195 ) to check for software errors. Hisense Firmware Downloads & Updates | Support