I am working on a Compaq Presario CQ50. When I power it up all I see is the power butten light and power light on LED. NO screens no promped NO CPU LED NO Drive LED I removed the RAM, Hard Drive and WiFi-Nic. still no promed of any type. So is it dead, or is there hope.

have you tryed just the mains with out the battery ,some laptops wont start if the battery is faulty,
or if the fan is full of dust and dirt and it can not turn, your laptop will not start.

may be overheating - try to clean heat silk and resolder CPU

To determine if the video card or LCD screen is faulty, please click on this link and follow my instructions.
http://www.fixya.com/support/r3598095-faulty_laptop_lcd_screen

Power up the external monitor first and then boot up the laptop, the video info will automatically divert to the external monitor.
If you do not see a Windows image on the external monitor then it is definitely a motherboard issue, because the video card is built in on the motherboard.
The Video card uses shared RAM (part of the RAM module/s ), try re-seating the RAM modules, also test the RAM modules.
You can test the hard drive by removing the hard drive and connecting it to an USB hard drive adapter, then connect the adapter into a working computer's USB port. If the hard drive is OK, this computer will see it as an external storage device and you can open the various folders and files on the hard drive.

Check This URL out from HP. It will help you.
Compaq Presario CQ50-100 Notebook PC series - HP Notebook PCs - Troubleshooting Black Screen Displays with No Error Messages During Startup or Boot - c01997899 - HP Business Support Center

Can you see what's on the screen if you hold it under a light? Did the screen die suddenly or were there more symptoms?

Have you tried replacing your ram.....In our repair shop we see bad ram causing problems like this all the time.We always check ram first...Rule that out first..then perhaps a new cpu.Cheaper than a mother board

The laptop might be overheating, sometimes when the laptop cant get any ventilation it shuts down and will not properly power up till the temperature issues are delt with.
But you usually get at least a few seconds of power before it shuts down again, so it may not be that, sounds a bit more like the CPU is dead and will need replaced.

Have you tried turning it on and selecting the function key combination for the screen? For example some screens use FN+F7, hold down the Function key and F7 to cycle between presentation modes.

key booard nad mouse is hangup only when your CPU utilization is 100%....just mimized the operation in task mager and then see it will not hang