Download latest Android 7.1.2 stock firmware PC version for Beelink GT1 TV Box from here, here or here. Download latest Android 7.1.2 stock firmware SD card version for Beelink GT1 TV Box from here, here or here. Download latest Android 6.0 stock firmware for Beelink GT1 Ultimate TV Box with AP6225 WiFi Chip from here.
Archive: GT1_704N0_AP6255 / GT1_704N0_AP6255_sdcard
Model: Beelink GT1 Classic and Ultimate TV Box with Amlogic S912 as CPU and with configuration 2GB+16GB / 2GB+32GB / 3GB+32GB / DDR3 or DDR4 with AP6255 WiFi/BT Chip
Image file size: 472 MB / 572 MB
Platform: Amlogic S912
Image name: GT1_704N0_AP6255.img / q201-ota-20170819.zip
Inside archive: firmware + factory_update_param.aml + recovery.img
Build number: Amlogic/q201/q201:7.1.2/NHG47L/20170819:user/test-keys
Caution: Please do not update firmware unless you know what you are doing, you really want it or it is absolutely necessary. Firmware updates may occasionally have bad results, like bricking your device, temporarily or permanently. The firmware update process is done entirely at your own risk. Before attempting to update the firmware, back up your data.