Why is my Screen is glitching

@christineh28103 "glitching" is not a very descriptive term. It would be great if you could tell us what it is that your screen does.

Since this happened after a water exposure, you will have to take care of this first.

Rice does not work. It does absolutely nothing to help you with this repair. All it does is waste time and waste food. Check here https://www.ifixit.com/News/30047/rice-i... for more on this.

For now, you must stop continuing to try to charge, sync or otherwise use your phone. This potentially can make a bad situation worse. This may further damage your phone.

The very first step I would take is to disassemble your tablet . Use this guide Lenovo Tab 4 TB-8504F Motherboard Replacement for that. Next remove the motherboard and the charging board. You will have to remove all the EMI shields from that board.

Next take a close look at all components and connectors. Look for major corrosion (green or white residue on the components), evaluate all the pins in the connectors etc,. Take a look at all connectors as well as cable ends. This also goes for the boards that you have not removed. Once you got any gross contamination cleaned, use 90%+ isopropyl alcohol and clean your parts some more. For a proper cleaning, use this guide. It was written for an Apple iPhone 3G but all the steps are still pertinent to your tablet as well. I can not stress the importance of a good cleaning enough, so do it over and over while replacing the alcohol after each cleaning.

The importance here is the cleaning. It would of course be best to get it ultrasonically cleaned Do not forget to replace the battery. This is a must and not an option. It will fail if you do not take care of it now.

After that, reassemble your tablet and re-evaluate. For as long as you have not cleaned your board and replaced the battery, everything is just a guess. Keep in mind that water damage is the hardest to troubleshoot and to repair. It is possible that you have a bad display assembly or the touchscreen. this video shows you how to replace those items. Replacing the display assembly may fix it. Even with all this, water damage has only a small chance to be fully repaired, but at least you can give it a try.