I'm trying to install Custom OS (ROM) on Android tablet( Lenovo TB-7504X ) with Android 7.0 .
Adb is properly set up and all the necessary images are downloaded, usb debugging and OEM unlock all settings checked, adb is also working while phone is on but it is not working on fastboot mode. device is not detected on fastboot mode.
i also tried installing different usb drivers but not working.
can anyone help me with what is missing here or what can be done.
In most cases like yours, the problem is that proper driver isn't installed. Check how your device is shown while in fastboot mode. If it's not "bootloader", then you have to install proper drivers. You can get official android drivers for adb from official android website, which will work in most cases.