Why is everything on my Galaxy S7 laggy, broken, and slow?

[Android Central Question]

I've had this phone for about 18 months now, and the phone has gone downhill very fast. There's a giant pink line going down the screen that appeared out of nowhere about a year ago and continues to grow, the screen is "stained" into a deep red with the shadow of the number pad for dialing phone numbers, every time I open an app my entire phone freezes, I can't delete messages, it takes forever to download or delete anything, my battery lasts 5 hours at most on power saving mode and only about 3 hours on no power saving mode, my battery percentage constantly drops from 50% to 6% in an instant, my phone runs out of power at 15% and up to 40%, i can barely ever charge it in general because it constantly says there's moisture in the port, and the thumbprint scanner has just stopped working entirely. I can't stand this thing anymore, and I know there's no fix to 90% of these problems, I just want to know what's causing it, so I know to avoid any and all phones like this one when my contract ends.

 

[B. Diddy]

Welcome to Android Central! The screen is failing and needs to be replaced, for starters.

It's worth trying a cache partition wipe to see if that improves the overall performance: https://support.t-mobile.com/docs/DOC-28028. If that doesn't help, then try booting into Safe Mode to see if the problem is due to an app you installed: https://support.t-mobile.com/docs/DOC-28008

The battery is also probably on its last legs. You'd need to get that replaced.

If you're getting a moisture alert, the phone probably has also had water damage at some point.

Unfortunately, even if the phone is still under warranty, it wouldn't be covered by it for these issues. Your best bet is to get a new phone. Sorry!

 

[L0n3N1nja]

You really should have gotten that exchanged when the screen started to fail, would of been covered in the 1 year warranty.

The moisture alert could be a faulty charge port, possibly a side effect of water damage.

Battery sounds like it's on its last leg, any idea how many charge cycles you've put that through? I've got an S7, still works but battery life is getting horrible but I've got nearly 800 charge cycles.

As mentioned above clearing cache could improve your performance, almost guaranteed to actually unless you already do it regularly.

Also you can reset settings without factory wiping the phone, did that to mine awhile back as it was slowing down and it helped. It's in settings under the back up and reset section.