Nexus 5, IMEI 0, how to restore IMEI? I dropped my old Nexus 5 on asphalt, and the phone display crashed.

I made a backup, buy new phone, and restored the backup on it.

But I did not know that before restoring I must take a backup of EFS.

So now when I dial *#06# I've got "IMEI 0" answer.

But phone can dial, works OK, but "IMEI 0" confuses me, and it's may be illegal to have IMEI 0.

Can I restore IMEI myself? I have no backup of EFS from new phone.
(There is no LG service centers in my local area.)
See this thread and scroll down to the EFS backup section-- efs contains "things like your MEID or IMEI... your data profiles.. radio settings." etc.

Usually backing up a phone (with clockworkmod recovery, for example) will back up the /data and /system partitions... maybe /cache... but not usually the efs...)

So I'm not clear if you're saying you've overwritten your new phone's EFS partitions  (/dev/block/platform/msm_sdcc.1/by-name/modemst1 and /dev/block/platform/msm_sdcc.1/by-name/modemst2) with .img files from your old phone?  Or perhaps with zeros?  Not clear exactly.

If you have the old phone still and can get into recovery, I bet you can probably still use the provided .zip to grab the efs partition backups.  Or, if you only have adb access, you can still probably dd them to the SD card manually.

If you choose to copy the old phone's EFS to the new phone, check to make sure it's legal in your area.  Anyway, hope this helps.