Unsolved
This post is more than 5 years old
2 Posts
0
818
August 15th, 2019 14:00
Latitude E7440 blank screen, bios reports unknown panel
The screen on my E7440 stopped working about 6 months ago after flickering a few times then going to a white screen never to come on again, and it’s been docked and used with an external monitor, with which it works perfectly fine, but the bios reports “unknown panel” and the resolution is reported as “0x0” or at times the resolution of the monitor I’m using with it. Is this a problem with the motherboard? I’ve also swapped in another of the same LCD and same result, running the lcd built-in self test results in a blank white screen, with no colors.
No Events found!
nyc10036
6 Operator
•
5.6K Posts
0
August 16th, 2019 08:00
You know the LCD is bad since an external monitor works.
Not sure what is the problem.
I184
2 Posts
0
August 23rd, 2019 02:00
Well that’s what I thought too, but even with a replacement lcd and cable it still does not function, I went ahead and bought a replacement for both on a hunch after posting this and replaced the screen, didn’t work, then the cable, still didn’t work.
Dell-Parnoshree C
2 Intern
•
309 Posts
0
August 23rd, 2019 03:00
Hi I184,
This seems to be an issue with the port on the motherboard where the LCD cable is seated, as you have swapped with known good LCD and cable and the issue is same. It works fine on the external monitor as the port used to display externally is different.
U2CAMEB4ME
6 Operator
•
6.2K Posts
0
August 23rd, 2019 03:00
Welcome to the Dell Community @I184
Disconnect the AC adapter.
Remove Main Battery.
Remove Base Cover.
Disconnect the CMOS/BIOS battery.
If you have a Meter it would be a good time to test the battery. "Should be 2-3 Volts"
Connect AC and power-on for a few seconds.
Try 3-4 times.
Reconnect the battery, reassemble and test.
Best regards,
U2