[Fire HD 8 and HD 10 Original Android Development] pascal009:
I have gone through the process like a dozen times, carefully following the OPs. The more I repeated it the less I understood the

workings.

I started with the disassembled device, the battery and the LCD ribbon cable disconnected.

Run

sudo systemctl stop ModemManager

sudo systemctl disable ModemManager

sudo ./bootrom-step.sh

... Waiting for ROM ...

I ground the test point on the PCB and connect the USB cable

... Remove the short and press Enter ...

On the Linux side everything looks good. The command ends with the message "Now it should reboot into a hacked fastboot mode".

Disconnect the USB cable. Reassemble (well, partially) the PCB, LCD ribbon and the battery. Press Power, device emits the familiar sound

as if it's going to boot up. The screen remains black. Nothing happens.

Notwithstanding, I connect the device to Linux box. Run "sudo ./fastboot-step.sh". Again, everything looks good on the Linux side.

The command ends with "Now device should reboot into TWRP interface". Nothing happens. The Power button does not respond to pressing in

any way possible. The screen remains black. "lsusb" does not show anything Android. "adb devices" does not see anything.

During the execution of bootrom-step.sh dmesg seems to recognize product as Android/omni_suez/MT65xx Preloader.

During fastboot-step.sh is shows product only as MT65xx Preloader.

For all practical purposes the device is not booting up.

[ 2259.075596] usb 1-1: new high-speed USB device number 22 using ehci-pci

[ 2259.386003] usb 1-1: New USB device found, idVendor=1949, idProduct=0280, bcdDevice= 1.00

[ 2259.386068] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[ 2259.386088] usb 1-1: Product: Android

[ 2259.386105] usb 1-1: Manufacturer: Amazon

[ 2259.386120] usb 1-1: SerialNumber: G000N60774740RS8

[ 2355.673227] usb 1-1: USB disconnect, device number 22

[ 2358.447579] usb 1-1: new high-speed USB device number 23 using ehci-pci

[ 2358.606457] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2358.606508] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2358.606528] usb 1-1: Product: MT65xx Preloader

[ 2358.606543] usb 1-1: Manufacturer: MediaTek

[ 2358.674055] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2358.674192] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2358.754600] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2361.118925] usb 1-1: USB disconnect, device number 23

[ 2367.031602] usb 1-1: new high-speed USB device number 24 using ehci-pci

[ 2367.334886] usb 1-1: New USB device found, idVendor=1949, idProduct=0280, bcdDevice= 1.00

[ 2367.334934] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[ 2367.334954] usb 1-1: Product: Android

[ 2367.334970] usb 1-1: Manufacturer: Amazon

[ 2367.334985] usb 1-1: SerialNumber: G000N60774740RS8

[ 2488.044101] perf: interrupt took too long (6680 > 6555), lowering kernel.perf_event_max_sample_rate to 29750

[ 2489.967861] usb 1-1: USB disconnect, device number 24

[ 2492.747571] usb 1-1: new high-speed USB device number 25 using ehci-pci

[ 2492.906387] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2492.906439] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2492.906460] usb 1-1: Product: MT65xx Preloader

[ 2492.906479] usb 1-1: Manufacturer: MediaTek

[ 2492.990902] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2492.991000] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2493.071691] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2495.416086] usb 1-1: USB disconnect, device number 25

[ 2505.979601] usb 1-1: new high-speed USB device number 26 using ehci-pci

[ 2506.172727] usb 1-1: New USB device found, idVendor=18d1, idProduct=d001, bcdDevice=ff.ff

[ 2506.172794] usb 1-1: New USB device strings: Mfr=2, Product=3, SerialNumber=4

[ 2506.172813] usb 1-1: Product: omni_suez

[ 2506.172832] usb 1-1: Manufacturer: Amazon

[ 2506.172848] usb 1-1: SerialNumber: G000N60774740RS8

[ 2509.785038] usb 1-1: USB disconnect, device number 26

[ 2510.135576] usb 1-1: new high-speed USB device number 27 using ehci-pci

[ 2510.335671] usb 1-1: New USB device found, idVendor=18d1, idProduct=4ee2, bcdDevice=ff.ff

[ 2510.335727] usb 1-1: New USB device strings: Mfr=2, Product=3, SerialNumber=4

[ 2510.335747] usb 1-1: Product: omni_suez

[ 2510.335762] usb 1-1: Manufacturer: Amazon

[ 2510.335775] usb 1-1: SerialNumber: G000N60774740RS8

[ 2519.213823] usb 1-1: USB disconnect, device number 27

[ 2521.979642] usb 1-1: new high-speed USB device number 28 using ehci-pci

[ 2522.138391] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2522.138444] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2522.138479] usb 1-1: Product: MT65xx Preloader

[ 2522.138493] usb 1-1: Manufacturer: MediaTek

[ 2522.222793] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2522.222888] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2522.303377] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2524.647729] usb 1-1: USB disconnect, device number 28

[ 2924.255596] usb 1-1: new high-speed USB device number 29 using ehci-pci

[ 2924.414454] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2924.414512] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2924.414532] usb 1-1: Product: MT65xx Preloader

[ 2924.414549] usb 1-1: Manufacturer: MediaTek

[ 2924.479086] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2924.479179] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2924.559936] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2926.924193] usb 1-1: USB disconnect, device number 29

[ 2942.347588] usb 1-1: new high-speed USB device number 30 using ehci-pci

[ 2942.506266] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2942.506347] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2942.506369] usb 1-1: Product: MT65xx Preloader

[ 2942.506385] usb 1-1: Manufacturer: MediaTek

[ 2942.589902] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2942.590002] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2942.670717] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2945.014756] usb 1-1: USB disconnect, device number 30

[ 2960.611573] usb 1-1: new high-speed USB device number 31 using ehci-pci

[ 2960.770458] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2960.770511] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2960.770535] usb 1-1: Product: MT65xx Preloader

[ 2960.770552] usb 1-1: Manufacturer: MediaTek

[ 2960.842289] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2960.842429] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2960.922930] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2963.287088] usb 1-1: USB disconnect, device number 31

[ 2978.603591] usb 1-1: new high-speed USB device number 32 using ehci-pci

[ 2978.762469] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2978.762525] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2978.762545] usb 1-1: Product: MT65xx Preloader

[ 2978.762561] usb 1-1: Manufacturer: MediaTek

[ 2978.838220] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2978.838358] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2978.918826] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2981.283134] usb 1-1: USB disconnect, device number 32

[ 2990.083596] usb 1-1: new high-speed USB device number 33 using ehci-pci

[ 2990.242457] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 2990.242506] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 2990.242529] usb 1-1: Product: MT65xx Preloader

[ 2990.242544] usb 1-1: Manufacturer: MediaTek

[ 2990.330160] cdc_acm 1-1:1.0: Zero length descriptor references

[ 2990.330302] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 2990.410858] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 2992.755118] usb 1-1: USB disconnect, device number 33

[ 3008.216874] usb 1-1: new high-speed USB device number 34 using ehci-pci

[ 3008.374491] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 3008.374569] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 3008.374594] usb 1-1: Product: MT65xx Preloader

[ 3008.374610] usb 1-1: Manufacturer: MediaTek

[ 3008.458288] cdc_acm 1-1:1.0: Zero length descriptor references

[ 3008.458431] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 3008.538900] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 3010.883266] usb 1-1: USB disconnect, device number 34

[ 3026.291580] usb 1-1: new high-speed USB device number 35 using ehci-pci

[ 3026.450353] usb 1-1: New USB device found, idVendor=0e8d, idProduct=2000, bcdDevice= 1.00

[ 3026.450417] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0

[ 3026.450433] usb 1-1: Product: MT65xx Preloader

[ 3026.450448] usb 1-1: Manufacturer: MediaTek

[ 3026.538207] cdc_acm 1-1:1.0: Zero length descriptor references

[ 3026.538344] cdc_acm: probe of 1-1:1.0 failed with error -22

[ 3026.619078] cdc_acm 1-1:1.1: ttyACM0: USB ACM device

[ 3028.963032] usb 1-1: USB disconnect, device number 35

~/Downloads/FireHD9/amonet-suez/amonet$