Monitor Flickering and blacking (electronic issue)

No sleep Neftali · March 7, 2021

Not sure where to begin with this so I'll be blunt and to the point. Its an ASUS MT276, it works for a couple seconds, has some flickering and a picture, a loud buzzing and then its gone. I took a video which i will post but its bad and does not do it justice. When the panel shuts off it is still powered on, the light indicator will show it to still be running as opposed to be all the way off or asleep. However there is still no picture or backlight anymore. I am well experienced in electrical repair and component replacements but an LCD is new territory for me. I opened it and removed the two boards, the power and controller board and found no visual issues with any components. Im ruling out backlight being dead since i was able to test those and found no issues. I am unable to find any schematics for this model so that's no help. If anyone has any ideas or is familiar with this issue and could tell me what it could possibly be i could replace the component(s) and get this thing up and running again. Im sure its easier to buy a new one I get that, but as of right now i cant afford one and even if i could i much rather upgrade to 1440, but still, cant afford it. Repairing and replacing components is more available to me. If anyone has any real ideas or is familiar with this type of issue, any suggestions would be helpful, or else im left with removing and testing components one by one still i find what's going on.

kirashi · March 7, 2021

7 minutes ago, No sleep Neftali said:

Not sure where to begin with this so I'll be blunt and to the point. Its an ASUS MT276, it works for a couple seconds, has some flickering and a picture, a loud buzzing and then its gone. I took a video which i will post but its bad and does not do it justice. When the panel shuts off it is still powered on, the light indicator will show it to still be running as opposed to be all the way off or asleep. However there is still no picture or backlight anymore. I am well experienced in electrical repair and component replacements but an LCD is new territory for me. I opened it and removed the two boards, the power and controller board and found no visual issues with any components. Im ruling out backlight being dead since i was able to test those and found no issues. I am unable to find any schematics for this model so that's no help. If anyone has any ideas or is familiar with this issue and could tell me what it could possibly be i could replace the component(s) and get this thing up and running again. Im sure its easier to buy a new one I get that, but as of right now i cant afford one and even if i could i much rather upgrade to 1440, but still, cant afford it. Repairing and replacing components is more available to me. If anyone has any real ideas or is familiar with this type of issue, any suggestions would be helpful, or else im left with removing and testing components one by one still i find what's going on.

Just because you cannot visually see any damage to the circuit boards inside the monitor doesn't mean a solid-state component hasn't failed. I used to see failed backlights (or backlight driver boards) in older laptops all the time when I worked in a retail electronics store that also had a repair department.

If you suspect the monitor is still "getting a signal" and not actually fully turning off, there's a strong chance either the LCD backlight or driver board is going/gone. Based on a quick Google search it appears the MT276 was released around 2010-2011 so I'd recommend upgrading rather than repairing.

Analog · March 7, 2021

That monitor is dead. From the sound of it there is something wrong with the power delivery in it. What exactly that could be, who knows. Unless you have a way of checking which component has failed, and that would require you to have information about the operating parameters of each, I am not sure if an attempted repair would be successful.