hello to everybody i need help. It is a laptop screen from the title and i dont usually fix them (only laptop and desktop motherboards) but i decided this time i will try and i need your help.
The laptop had shorted 19v main line that goes directly to this lcd with blown fuse on the motheroboard. I believe that somebody tried to check something with battery plugged and now we have what we have. On the laptop motherboard i replaced the fuse and laptop is now working but this screen is a problem.
In the attachment i am sending you what led board looks like in two parts. I marked with red two chips that were dead and i replaced them. First was NT50332B which i believe is a responsible for +3vled rail and second was NCP571MN12TBG which is voltage regulator. Before on this led board i had only 19 v, but now after replacing these two chips i have also 3,3 volt on coil marked green. I marked with blue all vital parts of the board that i have voltage but no picture on the screen. I noticed that on this third chip there is no voltage...and that seems strange. On those big capacitors marked blue no voltage and i believe those are responsible for powering that chip. That chip has markings NT50138B . I believe somewher there is a problem. I used thermal camera and nothing is getting hot. No short to gnd on capacitors. Please help what to check. Thank you!
https://ibb.co/C7dwhLj
https://ibb.co/bvYjQtJ
The laptop had shorted 19v main line that goes directly to this lcd with blown fuse on the motheroboard. I believe that somebody tried to check something with battery plugged and now we have what we have. On the laptop motherboard i replaced the fuse and laptop is now working but this screen is a problem.
In the attachment i am sending you what led board looks like in two parts. I marked with red two chips that were dead and i replaced them. First was NT50332B which i believe is a responsible for +3vled rail and second was NCP571MN12TBG which is voltage regulator. Before on this led board i had only 19 v, but now after replacing these two chips i have also 3,3 volt on coil marked green. I marked with blue all vital parts of the board that i have voltage but no picture on the screen. I noticed that on this third chip there is no voltage...and that seems strange. On those big capacitors marked blue no voltage and i believe those are responsible for powering that chip. That chip has markings NT50138B . I believe somewher there is a problem. I used thermal camera and nothing is getting hot. No short to gnd on capacitors. Please help what to check. Thank you!
https://ibb.co/C7dwhLj
https://ibb.co/bvYjQtJ
Attached Files