The KC901 has an upgrade function, you only need to save the ROM package you downloaded from the Internet to your TF (micro SD) card, follow these instructions to complete the upgrade, no other settings are required. Here are the steps to follow.
1、Applicable version
All publicly available versions of the KC901 support firmware upgrades.
The maximum supported TF card capacity is 32GB. large capacity TF cards may have compatibility issues, smaller capacity cards (less than 4GB) will have few compatibility issues.
KC901V and KC901M use the same firmware and the program will recognize the model by itself.
2、Upgrade steps
(1) Download the latest ROM file.
(2) After downloading, unzip the ROM package, make sure the file name and extension is Rom.bin, copy the ROM package into the root directory of the TF card. Then insert the TF card into the TF card slot located on the right side of KC901.
(3) Turn off the KC901 and then press the last three buttons of the top soft menu button (3.4.5 buttons from left to right) simultaneously.
After all three buttons are pressed simultaneously, briefly press the [CS] button and hold the three buttons in place until the firmware update screen appears.
(4) If step 3 is successful, the Upgrade Firmware screen will appear, and you will be asked if you need to upgrade. Select YES and wait for the upgrade to complete.
(5) When the upgrade is complete, KC901 will prompt you that it is complete, and after you press the YES key, the device will automatically restart and run normally.
Note: Do not unplug the SD card or insert the USB during the upgrade process.
3、Exception handling
In the case of an unsuccessful upgrade, the instrument may return an error message, or it may appear: the interface stays, a complete black screen, failure to power on, backlighting but no display, or other abnormalities. In either case, the device will not be damaged. Check if the TF card and ROM package are correct, then retry the upgrade.
If the system restarts or shuts down without a successful upgrade prompt, the program may not have been upgraded completely, and you will need to repeat the entire upgrade process until the upgrade success prompt appears.
In rare cases, the program may suddenly shut down during the upgrade process, and the upgrade function cannot be restarted. This is usually due to occasional abnormal behavior of the CPU and is universally unlikely to occur. When this happens, the upgrade program has erased the original firmware, including the firmware for battery management. Therefore, in this case, you need to disassemble the case, remove the battery, then plug in the charger and perform the upgrade again by following the steps in Section 2.
Each of the error messages is described below.
(1): SD card file system error!
Explanation: The file system on the SD card is corrupted, please use the card reader to format the TF card (FAT32), and follow the steps to upgrade again.
(2) Could not find the update file!
Please make sure that the ROM package has been loaded into the TF card and the name has been changed to Rom.bin.
(3): Error occurred while writing data in application memory!
Or：Written Data in flash memory is different from expected one!
Note: This error is usually caused by a failure to verify, please make sure the power is normal, the upgrade package is copied intact, and the upgrade package belongs to the correct model (to avoid confusing the upgrade package of other instruments), then restart and try to upgrade.