Plug the TV back into power. Some models will start the update automatically, indicated by a blinking standby LED.
If the TV is functional but requires a reset or fine-tuning after an update, you can typically access the factory menu by pressing on the remote. Update Guide for Akai & Nordmende TVs | PDF - Scribd Download P50 3663STV6 (1366 768) Nordmende USB zip
If it does not start automatically, hold the button on the TV (not the remote) while plugging it in. Plug the TV back into power
Do not turn off the power until the process is 100% complete. Once finished, the TV will usually reboot or return to a standby state. Factory/Service Menu Download P50 3663STV6 (1366 768) Nordmende USB zip