Depending on the exact firmware issue (of the above) you mean to remedy, you can either flash just the system/ANDROID file or all partitions. Excluding the preloader of cause. Below is the step by step guide on how you can proceed:
- Click on the Scatter loading button from the Sp Flash Tool interface
- Navigate to the M55CRD (downloaded) and extracted ROM or firmware folder through the window that pops up and select the scatter text file from there
- Untick the preloader (and all others files/partitions that you may wish to not flash if any).
- Ensure "Download only" or "firmware upgraded".
- Click Download - remove and replace the battery from the Mint Emerald M55CRD
- Connect the device to the PC through a USB cable WITHOUT pressing any key
- You get a red, purple and then yellow progress bar - the yellow one will proceed for some time
- Once done, you get green "Download OK" with a tick
- At this stage you can disconnect the device and attempt to power it on
- If it hangs on the logo screen for much longer, you can boot into recovery and wipe userdata and then retry booting it up again
Please ask any question you may have on the above tutorial on the comments sections below