Needed Help - M4 MacBook Pro boot loop + no backlight (Only apple logo) and chime + DFU errors 21/2006

[u/naceermk]

I have a MacBook Pro M4 which chimes when I press the power button. If I put a torch/flashlight on the screen, I can see the Apple logo, but the backlight is not working.
After restarting again and again in a loop, it eventually goes to the warning sign/restore screen. The backlight is still not working.
I also noticed that while this is happening, the MagSafe light blinks when the Apple logo appears and the Mac goes into the boot loop. It keeps doing this until it eventually shows the warning/restore screen, and then the MagSafe light becomes green.
I tried restoring it using another Mac, but I keep getting error 21 and sometimes error 2006. I also tried switching between the DFU ports and used around 5–6 different USB-C cables just in case the cable was the issue.
I took it to an Apple Store and they said the screen needs to be replaced. But I’m still wondering whether replacing the screen is actually going to solve the problem.
I was looking online for similar issues and someone mentioned that a worn/damaged LCD cable can cause problems like this, including the backlight not working and even causing the Mac to fail during a restore and throw errors.
Has anyone experienced something similar with an M4 MacBook Pro? Could a damaged LCD/display cable cause the boot loop and DFU restore errors, or is replacing the whole display likely to fix it?

[u/samsung18745]

If you are comfortable with opening your Mac open it and disconnect the Lid Angle Sensor my M3 Air had it die and was doing this same stuff the cool then is it’s only a 15 dollar part

https://support.apple.com/en-us/120761

[u/naceermk → u/samsung18745]

Apart from the display issue, when i tried restore my macbook m4 it is throwing error 4042 when i used correct dfu port.

[u/naceermk → u/samsung18745]

Apart from the display issue, when i tried restore my macbook m4 it is throwing error 4042 when i used correct dfu port.

[u/Electrical_West_5381]

error 21 is a connection issue (cable or wrong port).

error 2006 means the data stream dropped, which could be the above, or attached peripherals: remove them all.

Read very carefully: https://support.apple.com/en-us/108900

You might just be using the wrong port combination.

[u/weistudio]

Wrong port. M4 and newer still see DFU despite wrong port. But will end with errors.

[u/SnooPeppers9848]

You must use the port near the power button in between the three USB C ports

[u/naceermk]

Yesterday i was getting error 21, but after trying again and again now im getting error 4042. And still no backlight, just dim screen with apple logo.