If downgrade SBL1 in Moto E4 by flashing older bootloader.img on (bootloader unlocked phone or by fastboot flash sbl1 old_sbl1) the phone becomes bricked and it goes to Emergency download mode (EDL / QHS_BULK 9008).
by writing a backup of mmcblk0 (with at least a few hundred MBs - that contains sbl1 and other bootloaders) on good quality SD card is enough to fetch phone to bootloader/fastboot on many qcom Motorola phone. I think it works this way: if bootloader is erased or old in phone and it goes to 9008 and you put SD card with latest bootloader in it, then eMMC tries to boot from SD card. It is kind of secondary option for eMMC to boot or something else.... I remember I used to repair Samsung qcom and exynos phones this way a few years back.
How to create a 256 MB debrick/unbrick/super magic file from a working Motorola phones:
1. rooted phone by any means or unlocked bootloader + twrp.
2. with terminal if rooted type su first then : dd if=/dev/block/mmcblk0 of=/sdcard/debrick.img bs=1024 count=2621244
2a. with cmd if twrp: adb shell dd if=/dev/block/mmcblk0 of=/sdcard/debrick.img bs=1024 count=2621244
This will make a 256mb debrick/unbrick/super magic file on your sdcard....
copy debrick.img from SD card to PC or pull using adb pull /sdcard/debrick.img - writing file to SD card I believe is explained in the first post.
How to create a debrick file from E4 Verizon phone that cannot bootloader unlock or root ???
Well, you could use Verizon Software Assistant Motorola for this and connect a working phone on fastboot mode, it will download most recent repair file that includes mbm and mbm-ci - that contains blank flash
for many new Motorola phones.
Another way is by using MetroPCS /T-Mobile debrick file on Verizon phone (BB.32 bootloader is latest). Because both are MSM8917 CPU and both have BB.32 bootloader. Last time I repaired a Verizon phone with SD card method and using a debrick file from MetroPCS 64-6 version
. If you need file, let me know. I can upload it tomorrow....
Cheers guys!
---------- Post added at 10:34 PM ---------- Previous post was at 10:23 PM ----------
There is no need for SD card to detach, because fastboot mode will not flash anything on SD card.... It just boots from SD card and nothing else