Samsung SM-J500FN - Galaxy J5 - It fell into the toilet, it works but does not r

It fell into the hands of the Samsung SM-J500FN. A phone a month ago fell out of a toilet shirt pocket Total immersion. He was in the water for 1.5 to 2.5 seconds.
It is strange but the phone seems to work. It loads, starts, sees the network, connects to the internet, you can call it, the display is 100% ok.
Everything seems fine but touch doesn't work.
The startup graphics work smoothly, there are sounds, the phone looks normal without any fault.

I would like to start with a program diagnosis.
Anyone know any software for this model under Windows that can check if phon works at all?

Some tricks related to recovery etc. would also be useful.
Volume Up + Home + Power button = does not work

I found the firmware:
https://www.sammobile.com/firmwares/galaxy-j5/SM-J500FN/

but I don't know if it will be pressed to this model.
On the sticker I have:
SSN - J500FNGSMH

It was flooded a month ago
It's already dry. It has been working for a month and is not moist inside. It has already been charged three times.
I want to open it in the evening but first I will gather some info and software.

I meant more about some diagnostic soft + RecoveryMenu support from a PC so that in case of not pushing into unnecessary costs. I can't unlock the keyboard to test the phone and I don't know whether to push to buy a touch.
I will say it again - the phone is on. It works. Touch does not work.
How did the touch survive and the phone completely?
I would like to open it to visually check the disc. I unscrewed the screws but I have a problem with removing the body from the housing. I don't want to break NFC and other antennas either. Where exactly to pry the body to remove it?
There are instructions on the net but most often for J6 and others and they do not work.

If you can, give me a link to ADB, fastboots and others, especially to this JAVA application which allows you to control your phone from a PC - I don't remember her name.