It's not the inverter (assuming the display has one); that simply controls the backlight. It may or may not be the cable - likely it is not. It looks like a damaged display panel.
Run the LCD bist - Turn off the system and press and hold the "D" key + power button to turn on the system and it should run the LCD built in self test - see this link for more info - http://dell.to/1SkXNrG
This should help isolate if the issue is with LCD assembly.
Based on your description, since you state the external display works fine, like ejn63, I also suspect a faulty LCD.
You could choose to reseat the LCD cable and check - download the service manual here - http://dell.to/2bmbatc
You could try replacing the LCD cable if required at first, as it is a less expensive part - http://bit.ly/2csTAnb
Otherwise, the LCD needs to be replaced.
Also, please click my DELL-username and write me a private conversation with the service tag and your contact details(Name and Email) for case records.
When I tried the LCD BIST, the initial screens - White, Red, Green, Blue, which repeat for two cycles do not bring any changes to the vertical lines, but there is a last White screen, at which time the white color is uniform throughout the screen i.e. the vertical lines disappear. Also, I seem to get a diagnostic code on the keyboard status lights - the Num Lock blinks about once a second while the Caps Lock and Scroll Lock lights remain steadily on.
I tried removing the LED display ribbon cable and reseating it at both ends (motherboard / LED display end), but I am still getting the same display as before. I have ordered the cable, will try fitting the new one before ordering the Samsung 14.1 WXGA LED screen.
I see that there is a green integrated circuit behind the LED that also has a few ribbon cables going into the display. Would it help to remove the transparent plastic sheath at the back of the LED screen and try reseating any of the smaller ribbon cables connecting the green IC board to the LED panel itself? Thanks in advance for suggestions and comments.
Distorted lines seen during LCD bist indicate that the LCD is at fault. However, num lock blinking and other two lock leds stable - flashing, on, on - indicates a faulty motherboard.
I would not advise removing the sheath and reseating. However, that is your discretion.
Personally, I would suggest you to invest your money on a new machine if the motherboard and LCD are to be replaced as it would not be an inexpensive procedure.
I had ordered a replacement ribbon cable, which did not solve the problem. Next, I ordered and replaced the LED screen, the problem is fixed now.
I gather the motherboard has a defect too, but I will let the laptop run before the motherboard dies out completely. Will see how long it lasts, hopefully it will last a while.
Thanks for all the assistance in locating the fault.
Glad to hear that you have managed to resolve the LCD issue.
I would at this point advise you to backup imp data from time to time, if possible to an external drive or on the cloud, so that at any point if or rather when the motherboard fails, your imp files would be saved.
Should you need any info / help, contact us anytime.
ejn63
9 Legend
•
87.5K Posts
0
September 23rd, 2016 17:00
It's not the inverter (assuming the display has one); that simply controls the backlight. It may or may not be the cable - likely it is not. It looks like a damaged display panel.
DELL-Rishi
4 Operator
•
2K Posts
0
September 24th, 2016 12:00
Hi SADAPHAL,
Run the LCD bist - Turn off the system and press and hold the "D" key + power button to turn on the system and it should run the LCD built in self test - see this link for more info - http://dell.to/1SkXNrG
This should help isolate if the issue is with LCD assembly.
Based on your description, since you state the external display works fine, like ejn63, I also suspect a faulty LCD.
You could choose to reseat the LCD cable and check - download the service manual here - http://dell.to/2bmbatc
You could try replacing the LCD cable if required at first, as it is a less expensive part - http://bit.ly/2csTAnb
Otherwise, the LCD needs to be replaced.
Also, please click my DELL-username and write me a private conversation with the service tag and your contact details(Name and Email) for case records.
Let us know if you have any other queries.
sadaphal
7 Posts
0
September 26th, 2016 12:00
When I tried the LCD BIST, the initial screens - White, Red, Green, Blue, which repeat for two cycles do not bring any changes to the vertical lines, but there is a last White screen, at which time the white color is uniform throughout the screen i.e. the vertical lines disappear. Also, I seem to get a diagnostic code on the keyboard status lights - the Num Lock blinks about once a second while the Caps Lock and Scroll Lock lights remain steadily on.
I tried removing the LED display ribbon cable and reseating it at both ends (motherboard / LED display end), but I am still getting the same display as before. I have ordered the cable, will try fitting the new one before ordering the Samsung 14.1 WXGA LED screen.
I see that there is a green integrated circuit behind the LED that also has a few ribbon cables going into the display. Would it help to remove the transparent plastic sheath at the back of the LED screen and try reseating any of the smaller ribbon cables connecting the green IC board to the LED panel itself? Thanks in advance for suggestions and comments.
DELL-Rishi
4 Operator
•
2K Posts
0
September 28th, 2016 03:00
Hi SADAPHAL,
Thank you for the update.
Distorted lines seen during LCD bist indicate that the LCD is at fault. However, num lock blinking and other two lock leds stable - flashing, on, on - indicates a faulty motherboard.
I would not advise removing the sheath and reseating. However, that is your discretion.
Personally, I would suggest you to invest your money on a new machine if the motherboard and LCD are to be replaced as it would not be an inexpensive procedure.
Let us know if you have any other queries.
DELL-Hemalatha
4 Operator
•
2.8K Posts
0
September 30th, 2016 22:00
Hi , do give us a shout should you have any questions.
sadaphal
7 Posts
0
October 15th, 2016 18:00
I had ordered a replacement ribbon cable, which did not solve the problem. Next, I ordered and replaced the LED screen, the problem is fixed now.
I gather the motherboard has a defect too, but I will let the laptop run before the motherboard dies out completely. Will see how long it lasts, hopefully it will last a while.
Thanks for all the assistance in locating the fault.
DELL-Rishi
4 Operator
•
2K Posts
0
October 16th, 2016 15:00
Hi SADAPHAL,
Thank you for the update.
Glad to hear that you have managed to resolve the LCD issue.
I would at this point advise you to backup imp data from time to time, if possible to an external drive or on the cloud, so that at any point if or rather when the motherboard fails, your imp files would be saved.
Should you need any info / help, contact us anytime.