Question Motherboard or LCD , which is it ?

[Jack63SS]

I have an Acer Aspire 7551 that will not come up. Power on causes the Power led to light up and the CD drive click, but that is all. Nothing on the LCD (or an on attached monitor) and a bootable CD (or USB floppy) does not boot. Tried pulling out one of the two memory sticks and checking the CMOS battery, but nothing there either. I am willing to buy the parts to fix it, but I can't decide if it is the motherboard, the CPU or the LCD that is bad. Anyone have any suggestions or opinions ?
Thanks

 

[supermememaker26]

Does your keyboard light up for example the caps lock or the WiFi button on the keyboard or any lights on the keyboard? Because some laptops uses the lights on the keyboard for indication something is wrong

 

[Jack63SS]

The only lights that come on are the Power Button itself, the Power Indicator on the front edge and the Battery Status light, but neither power button flashes. Checked troubleshooting and I don't think they use the buttons for that, unfortunately.