[LeEco Le Pro3 Elite (Model x722) Guides, Developme] Hnk1:
Hi mate

Firstly, understand that signals are not only dependent on qcn and modem but also other partitions. Every company uses partitions in different order for a device to fully work. The partitions are usually around 40+.

Usually in twrp we can only see 5-6 of these. Not other partitions. One way is using Linux dd manually and other method is using an app on pc or android. You can check on playstore there are a few.

I prefer EFS Professional windows tool (find in Samsung forum). It helps you to know the partitions number, their order and helps

you in backing up but with newer android you need some more tools like ADBD.apk tool by chainfire to make your system insecure. Another method is by using command to mount your system partitions to be able to see these partitions. Every device almost uses slight different command to be able to mount system and this needs root of course.

I always make a full partitions backup before I play with any device (for future ) as it always help if qcn or other partitions do not help to restore signal.

Now, what can you do

If you have a backup of your partitions, restore them all one by one and if not, you need to ask someone on same android and build as you are to send you backup of his device. And you restore on your device and then revert back to your qcn for IMEI . However, some devices have a security feature that doesn't let you revert back to another device and you will get a hard brick. So in case of Sony you NEVER RESTORE PA partition from another device. Rest partitions are safe to restore.

I have no exposure with LEeco so I can't say for sure but I don't think it will have a security encryption like Sony which doesn't let you revert another device partitions. In LG, you can revert all partitions without a problem as long as android version and build date is same and you flash ALL partitions because sometimes you have boot of older android which is incompatible with newer android and thus you can end up bootloop or worse hard brick.

Another thing is you can find a full system stock ROM for your device which includes all 40+ partitions. Example is tot method has more partitions than kdz in LG devices but still at times this doesn't fully fix it. If your device has Qualcomm method (QFIL) if I remember correctly like many Lenovo devices (k5 plus , I have guide on it too) , that can be helpful.

Another thing is you find a person who has a box like octopus and ask him to repair your all partitions by extracting all partitions from your firmware (stock ROM , not your device's) and flashing it one by one . It is like reprogramming the device as every partition is wiped and rewritten again. But I haven't found many techs who know this and it is like JTAG. Many people will claim and trust me they know very little in terms of how android works or anything like that so they can mess your device too so be careful.

The best bet is if you have your own partitions and it has 100% success rate . Other methods are trial and error.

Second best is asking someone for all partitions and restoring them one by one and restarting every time after it to see if it is fixed. Make sure you BOTH ARE ON SAME FIRMWARE AND ANDROID VERSION/BUILD.

Other method which helped me at times are :

Sometimes flashing qcn of another device using same SOC also helps.

Sometimes flashing qcn of different Soc to fully break your signals and repairing them by flashing qcn of your device and then flashing stock helps.

It varies a great deal as what exactly is broken and we can't pin point usually.

If you are flashing your own qcn and you backed it up before you had this issue, there's a good chance you'll get it back but it's usually better to try someone's qcn who has his device fully working.

Good luck and update me in case you fix it so I know more about this and can help someone in future.