Hey Maartjie - Follow the below steps to try and flash/download the Mobicel Onyx's firmware or ROM afresh it attempt to remedy the boot loop.
- First download and extract the Mobicel Onyx's firmware or ROM from [ROM Download].
- Also download and install/extract the following: SP Flash Tool
- Install the MediaTek Preloader USB VCOM drivers as per the tutorial here
- Launch the SP Tool from the extracted folder
- Click on the Download tab
- Click 'Scatter-Loading' > browse to and locate the scatter file from your extracted firmware files
- Connect the Mobicel Onyx to the computer via a compatible USB cable without the battery
- Then click on the Download/Start button and then install the battery so computer can detect and connect to its system
- The flashing process should then start with progress bars and you should get a green cycle with a white tick and the text 'Download OK' when the flashing is completed. At which stage you can safely disconnect the your Mobicel Onyx device and power it on for a re-setup.
NOTE: We can flash the device for you remotely (over the internet) for R100 If you are not comfortable flashing the device yourself. Read more here