A1707 Water Damage - LCD and Touch Bar not response

I would stop using the system and disconnect the battery so as not to damage things any further! Water or any liquid can fester causing more damage and with the addition of power will speed it up.

At this point you’ll need to take the logic board out to inspect the damage, the Touch Bar connects to it. Look for corrosion damage. Depending on where the spill hit you might need to also check the T-CON board for damage as well. which can explain the lack of display.

Replacing the cable likely won’t fix anything. I’m suspecting you have corrosion damage on the logic board and the T-CON. This gets into if you can clean the corrosion off to get things going again or the need to get to someone who has the deeper skills to fix your system or if replacing is the only direction. This could be quite expensive!

To get to the T-CON so you can clean it, you’ll need to remove the display following this guide MacBook Pro 15" Touch Bar Late 2016 Screen Replacement

The logic board will likewise will need to be removed as well. Sadly, we don’t have a guide for that but its mostly obvious when you review the teardown here MacBook Pro 15" Touch Bar Teardown and after you’ve removed the display assembly following the display guide.

Take some well lit and sharp pictures of what you find and post them here Adding images to an existing question

You’ll need a soft tooth bush and 85% reagent isopropyl alcohol being careful not to pull off any of the small components. You will need to pull off the metal shields carefully as they need to be put back. This is not an easy job and you still likely have damaged components! You can’t just replace the displays backlight fuse as there’s more to it than that.

After cleaning the liquid spill for the two boards You’ll then need to look at boardview drawings and schematics to figure out what got damaged in the areas you located the damage. Then the hard part locating the needed replacement parts.

As you can see this is quite a big job! I personally would ship my system to someone who does this for a living! They have the needed skills, tools and access to parts. The other approach is just replace the assemblies which gets into quite an expense in your case!

Do you have data on your drive you need to gain access to? You might try booting the system up in Target Disk Mode after you’ve cleaned things up.