Brightness problem after A14 5G screen replacement

[John Veness]

Hi, I replaced a broken screen on my son's Samsung Galaxy A14 5G. Everything seemed to go OK except for one problem:

When we change the screen brightness using the on-screen slider, the actual brightness goes up and down several times over the length of the slider, rather than from dim to bright in one smooth range.

Any ideas?

[Tourbillon De La Vie]

Who changed the panel

[John Veness]

I did.

[Tourbillon De La Vie]

Original Samsung panel or some generic one? If latter explains the issue
Try
https://apps.samsung.com/appquery/appDetail.as?appId=com.samsung.android.app.repaircal

[John Veness]

Here is a video demonstrating the problem. https://youtu.be/L_N_nWLRmOA 

If I'm looking at it correctly, it seems to loop through the brightness range about 8 times over the range of the slider. Maybe the original screen had, for example, 256 brightness levels, and the replacement one only has 32 levels?

I thought it was an original Samsung screen (with frame) but maybe it wasn't.

The Self Repair Assistant app isn't compatible with the A14 5G, unfortunately.

[John Veness]

It turned out to be something wrong with the screen. I suspect three binary digits worth of brightness information wasn't being transmitted from the phone to the screen, i.e. three damaged pins or three damaged traces on the cable - that would explain the way it seemed to repeat 8 times over what should have been the 0 to 100% brightness range.