The most problems here lost imei cannot change imei with any tools, what wrong ? caused by " BASEBAND ANDROID LOST " (must to fix it, before changer the new imei)
How to known if baseband was Lost or damaged from android smartphone :
Open - Setting - About Phones - Look "Baseband version".
If show Baseband Unknow , we must repair baseband then we can do to write imei.
The Acer Z200 imei invalid after format with flashtool (Baseband Available but Imei Null) how to repair ?More solution for changer imei without using the Computer :
1. Make sure USB Debugging ON and Download Acer Z200 Drivers for all windows supported
2. Root acer z200 untill real success
3. Download and Install MTK Droid Tool
4. Open Mtk Droid Click Root and the following step by step until success.
5. Click Change Imei from Mtk Droid Softwares
6. Input your phone imei back cover battery
7. Click Reboot
8. Wait untill Phone reboot and will Show your Phone imei also can check *#06#.
1. Download => Chamelophone apk
2. Instal in your smartphone [MTK Android]
3. Open the application [Chamelophone] and insert your 16 digit imei.
4. Click apply and make reboot your device.
* This method must be rooted device will working only.
If still on firmwares problem, can found here how to => flashing with original firmware. acer z200 and imei inside the firmware files.
On this tutorials, I really hope can solved your problem about it, always check my latest post about any other android flasher and tutorials.