I have a Dell Latitude D800. I want to run it on AC power. Do I have to take the battery pack out of it before I ru it on AC power?

For latitude there's not much to do. check the power adaptor/connecting pin --- if any problem. If not than u need to replace the board.

First make sure that computer is getting power, check that AC adapter is connected and led light is on.
Second, remove the battery from laptop and all the cables. Press power button down for 10s. But the battery back on, connect AC adapter and try to start. If still nothing, possible HW issue.

The Dell Latitude D800 series of Notebook PC's, uses an AC adapter that puts out 19.5 Volts DC. 90 Amps. (Amperes)

This is one example I found from a quick search,

http://www.acadapterz.com/product_26527.html

Regards,
joecoolvette

There's a "slide-away" coverv on the bottom of the laptop, where the docking-station's adapter would connect. Manually slide the cover, and inspect to ensure that there's nothing stuck there that is "tricking" the laptop into claiming that it is docked.

Plug in the AC power cord, remove the battery, and try powering up. Anything? Any lights?
Remove power cord, hold in the power button for 30 seconds, then try plugging it in again and powering up without the battery. Any change?

Check the status of the battery directly from the battery. Turn the laptop over and on the batter is an battery indicator button and lights to tell you if it's charged. If it is charged then you have an problem internally. Wiggle the tip of the power cord at the laptop connection to see if it is loose, if it is then you have an loose connection on the motherboard which can be fixed by an experienced tech that can solder or the motherboard will need to be replaced.


IF THIS HELPS PLEASE VOTE.....GOOD LUCK AND THANKS..

Okay, I had that problem with my HP less than a minute ago.

Maybe it is the same problem. See if the battery light comes on. Press the power button again and again if it doesn't start, for some time. It may show the boot screen and hang. Now, the battery must be charged. Shut it down directly and switch the AC off.

Now, switch it on and see if the battery light comes on. If it does, it is the same problem as mine. Now, turn the PC over and remove the battery carefully. There may be switches for that.

Now, plug in the AC and start it without the battery in. If it does, you're done. Now, plug in the battery again.

remove the battery from the system and try to power on the System with the AC adapter connected. its only to check whether the system is receiving the power .

Also press the Fn key holding it down press the power button and release both the buttons , look for the LED codes and do let me know abt it

This may be SpeedStep slowing the processor to save battery life. It speeds up when it is needed.