[Q] Device locked and system image reflash required - a deadlock situation - E 2015 Q&A, Help & Troubleshooting

I got the key and used "fastboot oem unlock <key>" to unlock the device. Replace the logo.bin so that the warning messages goes off. After that I locked the phone. Following is the screenshot.
# fastboot oem lock
...
(bootloader) Phone is locked successfully!
(bootloader) Please reflash system image before reboot the phone!
OKAY [ 1.595s]
finished. total time: 1.595s
Now the phone remains in fastboot mode because it cannot boot (system image issue.). While unlocking it says,
# fastboot oem unlock W3YRQHWOSLI2V7OVUI4L
...
(bootloader) Check 'Allow OEM Unlock' in Developer Options.
FAILED (remote failure)
finished. total time: 0.007s
It is a deadlock situation now, I cannot change the option because the phone does not boot to access Developer options and cannot flash because it is locked. (The display says Device is LOCKED. Status Code: 2, Software staus modified.)

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I think this is the answer of your question : http://forum.xda-developers.com/showthread.php?p=59564073

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dulce.ai.angel said:
I think this is the answer of your question : http://forum.xda-developers.com/showthread.php?p=59564073
Click to expand...
Click to collapse
Thanks a lot for the quick response. Looks better now. At least not flagging Check 'Allow OEM Unlock' in Developer Options'. but transformed to 'Preflash validation failed' , not sure if it means the same as before. The response is as below.
# mfastboot flash boot boot.img
target max-sparse-size: 256MB
sending 'boot' (32768 KB)...
OKAY [ 1.038s]
writing 'boot'...
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 1.664s
When flashing system images it gives:
# mfastboot flash system system.img_sparsechunk.0
target max-sparse-size: 256MB
sending 'system' (262143 KB)...
OKAY [ 8.231s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 8.638s
Gives Invalid signed image. As from fastboot screen, the product variant is "sunria XT1521 8GB P3" of Moto E 2015 4g LTE, country - India. Used the same image as refereed above "XT1527_SURNIA_RETUS_5.0.2_LXI22.50-24.1_cid9_subsidy-DEFAULT_CFC.xml.zip"
Still hopeful to bring it back. Any more clues ..

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[Q][CLOSED] Device locked and system image reflash required - a deadlock situation
rakeshv62 said:
Thanks a lot for the quick response. Looks better now. At least not flagging Check 'Allow OEM Unlock' in Developer Options'. but transformed to 'Preflash validation failed' , not sure if it means the same as before. The response is as below.
# mfastboot flash boot boot.img
target max-sparse-size: 256MB
sending 'boot' (32768 KB)...
OKAY [ 1.038s]
writing 'boot'...
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 1.664s
When flashing system images it gives:
# mfastboot flash system system.img_sparsechunk.0
target max-sparse-size: 256MB
sending 'system' (262143 KB)...
OKAY [ 8.231s]
writing 'system'...
(bootloader) Invalid signed image
(bootloader) Preflash validation failed
FAILED (remote failure)
finished. total time: 8.638s
Gives Invalid signed image. As from fastboot screen, the product variant is "sunria XT1521 8GB P3" of Moto E 2015 4g LTE, country - India. Used the same image as refereed above "XT1527_SURNIA_RETUS_5.0.2_LXI22.50-24.1_cid9_subsidy-DEFAULT_CFC.xml.zip"
Still hopeful to bring it back. Any more clues ..
Click to expand...
Click to collapse
Yayy !!!! I could bring the phone back to life after a day of coma.
@dulce.ai.angel - thanks for referring to squid2 link, must read for all fiddling with the device.
My 2 cents on it.
The problem was region. The build referred above refers to US ( .._RETUS_5.0.2...). I could get the image for the build for ASIA, pl search. I am too young on this group to put a external link (please drop a PM if needed for this).
With the Product name appearing on the initial fastboot string, Region, version of android, you will be able to makeout the right firmware. As for me the it was XT1521_SURNIA_RETASIA_DS_5.0.2_LXI22.50-53.1_cid7_subsidy-DEFAULT_CFC.xml.zip
Enjoy!!!!