This is the only solution for solving Tecno KA7 Fastboot Error. Using this method is not only safe but it is a sure way to revive a dead Tecno KA7.
All you will need is,
If the phone is totally bricked and its not detected by PC, just open the back cover and disconnect the battery and flash it without battery, then after flashing insert the battery.
Check-out my YouTube video below for step by step tutorial