Turn off the TV, insert the USB, and then power it on. Some models require holding the power button or navigating to Settings > Support > System Update > Update via USB .
It looks like you're searching for specific firmware files to repair or update a TV (using the MS6486T PB753 Go to product viewer dialog for this item. motherboard with a 1920x1080 resolution). Download MS6486T PB753 1920x1080 Hisense 43N2170 part2 rar
This is a common source for these specific board-level files (MSD6486T TP.MS6486T.PB753). You can check their firmware file listing for the exact archive you mentioned. 3. How to Update via USB Turn off the TV, insert the USB, and then power it on