PC No Longer Displays on my Dell Monitor.
 

I tested my monitor on three computers: the monitor still works on the first computer: the monitor use to work with the second computer back when that computer would boot up: and the last computer (the laptop) boots up but will not input into the external monitor at all: read about these three computers as follow:

1. My external Dell flat-screen LCD (not CRT) monitor still works with our old Microsoft ME (ten or so years old) computer tower. I just tested this yesterday. This old computer will still output into my monitor.

2. My new Ubuntu 11.04 OS computer tower only outputs to the monitor when it successfully boots. The motherboard has a display spot that displays numbers and/or letters. When it says FF it boots up to Ubuntu successfully. It will first say 01 when the power is on, before I turn it on. Them when I turn it on, it displays 03 for a second, and then a bunch of other numbers before displaying FF when it does boot successfully.

The last several days, since my tower will not boot up, it does not display a bunch of numbers. It may still start at 01, flash 03 maybe, but regardless, within a second (literally) of turning it on, it displays the number 90 on the motherboard and ot foes not boot up. I tried removing things off the motherboard. Several days ago that worked, and after waiting a falf an hour, it would boot back up, after removing some of the things, like cards, or RAM, or drives hard drives, and putting them back in. I know a little since I know how to build computers. Someone told me that FF means that it successfully boots up to the or a operating system. I can assume that much.

But that doesn't work anymore. It just says 90.

3. Since my Ubuntu 11.04 (OS) laptop has a broken screen, I have had my laptop connected to my (external) monitor. I bought this monitor in 2011 September. It has worked perfectly before.

I pulled off the display cord off the laptop, a few different times, the last month or two, so that I could connect the monitor to my tower, and vice versa while the tower and the laptop were both still on.

Before, that disabled display on the moitor several times before. But it would start working again eventually.

But after several days of trying everything, the laptop will not be display on the monitor.

The orange light, on the monitor, flashes white if it (the monitor) is turned on, or if I connect it to my laptop, but then the monitor will say that no signal is being recieved, that the computer that it's connected to is off. But I know for sure that my laptop is turned on because I can still see a part of the broken laptop screen that will show the Ubuntu desktop. I will see that on the broken laptop screen.

But the external monitor (that has worked many times bfore for this laptop) will say that nothing is coming in, no signal.

But when I connect this same monitor to that old computer, it displays perfectly.

So, it's not the monitor.

<Fn><F8> - Switches the video image to the next display option. The options include the integrated display, an external monitor, and both displays simultaneously.

Sounds like the laptop display is set to the Integrated display only mode if I'm reading your post correctly.

Fn + F8 didn't work. I also tried other keys, other combinations. My laptop has a broken screen. That is why it is connected to this external monitor. It use to work. I bought a brand new monitor. It worked for a month or so. The monitor still works for this other computer. That means it's not a monitor problem. Maybe there is something else I can press to make the laptop output into the external monitor.

I am not sure if it is on an integrated mode only or not. I don't know what that is exactly. You should tell me more about that. But I still don't understand why the settings would all a sudden change out of nowhere, in the middle of nowhere.

Did the laptop's video card go bad?

I read about that possibility. A website writes: If your monitor works on another computer it is safe to assume that the video card or potentially the motherboard within the computer is bad. That is from this website: http://www.computerhope.com/issues/ch000241.htm#04

My second computer, on the motherboard, it displays 99, and then it fails to boot up. This one website shows a possible meaning to this 99: 99 Check for SMART drive (optional): http://www.bioscentral.com/postcodes/phoenixbios.htm#