Shows only on lowest dim setting? All in on cable? logic board? PSU?

Hello,

I’m only getting a display on this A1267 24’’ Cinema Display when I put the dim setting to the lowest setting.

If I start to increase it by 1% I can see it start flickering.

If I put it really high the display will go off and if I bring the setting all the way back down it does not come back on. I’ve also verified that the speakers are still working when the display turns off, so therefore there is still come kind of power going to the monitor.

The only way for me to turn it back on is to lower the setting all the way back down again, unplug power and replug it back on. However, pretty useless on the super lowest brightness setting.

My question is could this be a power supply, logic board, or all in one cable problem, or is it something else.

Also, there was one time after playing with it for awhile, I was able to bring the screen all the way to it’s brightest setting, I tried putting the computer to sleep and turning it back on and it came back on as normal. I then proceeded to try and unplug the power and replug it back in, the monitor flashed and it did not come back on. I had to adjust the setting back to low, unplug, replug, and it is back on, I’ve since had no luck in getting it back to it’s highest brightness setting.

Please help. Thank you.