I finally got the replacement display to wake up and show actual colour output—but it’s only showing a vertical colour bar, not a full image yet. Still progress!

What’s Working

• Display handshaking successful: After tweaking your initialization sequence, the screen now responds correctly—colour input is visible.

• Registers are behaving: COLMOD, MADCTL and COLCTRL settings now register properly—colours (albeit limited) are appearing as expected.

That’s a big step over “nothing at all.”

Current View: Just a Vertical Bar

Despite the screen lighting up, the output remains a vertical bar—static or shifting—but no actual framebuffer image is rendering.

This scenario typically points to one of two culprits:

1. Timing/synchronization mismatch—porch widths, active edge polarity, or sync pulses might still be slightly off.

2. Data bit misalignment or wiring error—only one set of colour bits (e.g., blue) is being correctly mapped, while red/green are getting lost or misinterpreted.

Next Steps on the To-Do List

Here’s the investigative roadmap I’m following to resolve it:

** 1. Double-check timing configuration** Align the Raspberry Pi’s DPI parameters (hfront / back-porch, hsync, vsync, pclk) against known working examples from similar screens

** 2. Revisit wiring and bus mapping** Ensure the display’s RGB lines are properly connected:

** 3. Explore differential init commands** Compare init sequence with any other similar panels that I can find, their may just be gold 

link to frambuffer video

https://cdn.hackaday.io/files/2033918701880544/LCD_frame_buffer_responce_to_col.mp4

link to current semi working INIT

https://cdn.hackaday.io/files/2033918701880544/HV_mode.ino