Yes, you will have to open up the system to check the cable. It may be that the cable is loose but considering that something spilled on it the problem could be the cable is shorted or that the connection needs to be cleaned. But at worse it may be the cable and possibly the screen will need to be replaced. But open it up and have a look it may be something easy to correct.

You did not post the exact model of your system and without that I cannot direct you to the correct service manual for instructions on opening the system and accessing the cable and screen.

I have a similar issue except nothing was spilled on it. 

Dell Inspiron 3542 Laptop with a 2000-0415 error but everything other category came out with flying colors. 

when I open the laptop, what do I look for

Before taking anything apart, can you get a screen self-test to run (hold the D key while powering up)?

Hello

I have a dell E7450.  I am getting the error code 2000-0415 when running the onboard diagnostics.  The keyboard backlight does not come on. The keyboard does not work and the touchpad also does not work.  Laptop does work with external keyboard and mouse.  I have checked the ribbon cables and reseated them several times.  I have also removed the CMOS battery and placed it back after 5 minutes to clear the CMOS.  Could this be a problem with the keyboard or the motherboard?  How do I isolate and test further?  Thanks.

Press key "FN" + "s" + "v" with the Laptop started and press the power button. The screen go down and black (system down) after press the power button and keyboard and mouse and does working.

Or, Shutdown the laptop, press key "FN" + "s" + "v" and press the power button, keyboard and mouse does working.

@juliocomj the problem is gone, thank you