Hi all.
Some time ago I have bought a supposedly non-working laptop for spare parts (mainly case and touchpad) for my other one. The seller said the is no picture (no image and no backlight), but the screen is perfectly fine.
I turned out it kinda is working, after connecting to external monitor through HDMI port, the picture was there and the system works fine.
I decided to try and get to the bottom what is wrong with it - and I did, partially thanks to the information and boardview I found on this forum - thank you!
There was a short on the lcd power circuit and after replacing the damaged component (logic gate) the screen started to work! But not fully as supposed to, see the attached photo.
The problem occurs not only in Windows, but also in bios and on system loading. It seems the screen is not correctly recognized and the laptop doesn't know what resolution it should display (it's 1024x768 in Windows and it can't be changed, the screen itself is 1920x1080)
Switching the screens with my other laptop (it's the same model, bo differs a bit) doesn't work - this one uses 1920x1080 screen with 30-pin EDP connector, the other one 1280x720 (I think) with 40-pin LVCD connector - switching screen (with cable) doesn't work on either of them (different display signal I guess). I also have second EDP cable, but after switching the problem is still there.
My questions is, what is the most probable reason for this issue? How is the screen identified by the laptop? Is there some return signal that may be missing (I checked for cable continuity and it should be fine)? Is the screen itself can be damaged? Or something else on mainboard? Is the screen incompatible with the laptop (that would also mean it was replaced before selling, but why)?
Some time ago I have bought a supposedly non-working laptop for spare parts (mainly case and touchpad) for my other one. The seller said the is no picture (no image and no backlight), but the screen is perfectly fine.
I turned out it kinda is working, after connecting to external monitor through HDMI port, the picture was there and the system works fine.
I decided to try and get to the bottom what is wrong with it - and I did, partially thanks to the information and boardview I found on this forum - thank you!
There was a short on the lcd power circuit and after replacing the damaged component (logic gate) the screen started to work! But not fully as supposed to, see the attached photo.
The problem occurs not only in Windows, but also in bios and on system loading. It seems the screen is not correctly recognized and the laptop doesn't know what resolution it should display (it's 1024x768 in Windows and it can't be changed, the screen itself is 1920x1080)
Switching the screens with my other laptop (it's the same model, bo differs a bit) doesn't work - this one uses 1920x1080 screen with 30-pin EDP connector, the other one 1280x720 (I think) with 40-pin LVCD connector - switching screen (with cable) doesn't work on either of them (different display signal I guess). I also have second EDP cable, but after switching the problem is still there.
My questions is, what is the most probable reason for this issue? How is the screen identified by the laptop? Is there some return signal that may be missing (I checked for cable continuity and it should be fine)? Is the screen itself can be damaged? Or something else on mainboard? Is the screen incompatible with the laptop (that would also mean it was replaced before selling, but why)?
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