The thing that you need to keep in mind, if you need to flash a custom ROM or new Rom for your MTK device make sure it is compatible with your model and sub model.
If you able to enter into the system, please write down your original software version, so that if you mistakenly flash the ROM you still have info about the previous working ROM and you can download the stock ROM or factory ROM of your device.
So that our customer brought his Lenovo A850, problem with the system infected with adware type of apps, porno apps which caused the system not responding, heavy and lagged.
As our previous experience, this kind of problem which cannot solved by resetting to factory,
the solution are either root your device and installed Titanium Backup Pro version, and you can uninstall unwanted apps through the Titanium Backup Pro, but you have to extra careful not to uninstall the system files, With Titanium Backup actually, if you doubt, you can backup the apps before unistall, so if it caused your system a problem you can restore back the apps.
Another solution, which you can clean install with a new firmware, which we like the most because, it is a 99% clean and refresh.
before performing flashing do necessary backup to the NVRAM folder which store information about imei, baseband and networking. If it missing or corrupt you will face problem like undetectable Sim, unable to make call and data.
Advisable to pick the official released firmware instead of custom. And if its official make sure it’s compatible with your original ROM because there a lot of submodel of the device for example a850 got variant of a850i, a850+ and the firmware will not compatible to each other and will cause brick to the phone:
As our case here, this lenovo model A850 Europe Version with ROM version A850_203_sjrom.com.cn, and as we thought this model similar with our previous A850 firmware that we normally used but wasn’t, which A850_203 supposed made for Lenovo A850i, so that we wrongly flash and caused the device brick.
The symptom of brick phone after wrongly flash Preloader are your phone will completely dead, unable to charge, unable to turn on, no recovery mode, undetectable via USB VCOM Preloader and undetectable to PC at all,.
But, hey there are some good news, your MTK65xx brick device still can be revived, but not 100% for all model, but we can guArrantee on Lenovo A850 MTK6582.
Well, you need to prepare the stock ROM or firmware that is similar version or compatible version with your model, that’s why important to jot down the original firmware version before reflash. For this model we pick the official ROM for A850i came with A850_203 multilanguage firmware.
MTK 65XX metamode driver – USB VCOM Preloader driver, if you previously installed then there is no need.
SP Flash Tool to download the firmware to the phone.
Run SP-Flash Tool, map the scatter loading MTK6582 for your firmware, normally inside the firmware folder. It will mapped the necessary file and partition for your device, After that click Download and leave it searching for device, it will start flash when found the device,
so next we need to activate back the dead of Meta mode USB Vcom MTK65xx , firstly remove the battery, simply press and hold VOLUME UP & DOWN + Power Button simultaneously while reinsert USB that connect the phone to PC.
The previous SP Flash that searching for device will start the download process just after the META mOde activated, if you failed then try repeat the step.
After the dowload finish, if your downloaded firmware match and compatible, your device should vibrate and turn ON back 🙂
Good Luck, if you need necessary advise whatsapp me through 0142871121