Ensure the physical (the physical button array for power, volume, and menu) is securely connected to the board, as its status LED acts as your progress indicator.
Use an SPI Programmer (such as the cheap and widely available CH341A Programmer ). You can use an SOP8 IC test clip to clamp onto the chip without desoldering it, or desolder the chip entirely for a cleaner read/write.
: Fixes distorted, solarized, or negative-looking colors caused by bit-mapping mismatch between the motherboard and screen.