When my 6 year old Latitude C800 died recently, I searched and found a used Latitude C840 with a broken LCD panel on eBay. I researched and noted that BOTH the C800 and the C840 used the same 15" LCD panel, part number: 1K855. Since my LCD was still operable, and the C840 was priced right, I decided to go for it and bought the C840.
When I connected the C840 chassis and my old LCD together to make my completed (new) laptop, the LCD would not work. I can use an EXTERNAL monitor and see the bootup process. I even installed the OS (XP Pro) using the external monitor.
I tried swapping the graphics card from the C800 and installing it on the C840 without any success. I thought I may have figured it out when I went into the BIOS setup and changed the display settings from “docked” to “system.” However, that also failed to correct the issue.
What I see on the LCD is a 2 inch, solid gray band across the bottom ¼ of the screen. I cannot see the BIOS POST or anything other than the gray band. That gray band goes away whenever it gets to the Windows XP boot process.
As stated previously, the display appears perfectly on an external monitor. I can see that all of the drivers are loaded and are working properly according to the XP DEVICE MANAGER. The SYSTEM BIOS is flashed to A13 and is the most current BIOS for the C840.
I am stymied. I thought the LCD panels on the C800 and C840 were one and the same. According to Dell support, where I compared the two exact models by referencing their specific service tag numbers, I am correct.
I see the LCDs being sold on eBay and they’re listed compatible with C800, C810, C840 and even some Inspiron models as well. I figured that I was safe to use my old one with this new mobo.
Anyone here have any ideas on what I might do to correct this issue?
I tried swapping the graphics card from the C800 and installing it on the C840 without any success. I thought I may have figured it out when I went into the BIOS setup and changed the display settings from “docked” to “system.” However, that also failed to correct the issue.
What I see on the LCD is a 2 inch, solid gray band across the bottom ¼ of the screen. I cannot see the BIOS POST or anything other than the gray band. That gray band goes away whenever it gets to the Windows XP boot process.
As stated previously, the display appears perfectly on an external monitor. I can see that all of the drivers are loaded and are working properly according to the XP DEVICE MANAGER. The SYSTEM BIOS is flashed to A13 and is the most current BIOS for the C840.
I am stymied. I thought the LCD panels on the C800 and C840 were one and the same. According to Dell support, where I compared the two exact models by referencing their specific service tag numbers, I am correct.
I see the LCDs being sold on eBay and they’re listed compatible with C800, C810, C840 and even some Inspiron models as well. I figured that I was safe to use my old one with this new mobo.
Anyone here have any ideas on what I might do to correct this issue?




