Waveshare Pioneer600 - OLED screen stopped working

Hi iFixers. Me again with yet another weird question - I have a Waveshare Pioneer600 hat for the Raspberry Pi and at some point I discovered to my surprise that OLED screen stopped working. It died with small steps - at first it stopped being detected over I2C but kept working if addressed via Python code, but now it just died.

Btw the screen itself works fine - I soldered it onto another carrier board and it's totally fine. So the issue is probably on the board.

Here is an official wiki of the board: https://www.waveshare.com/wiki/Pioneer60...

And here's overall board layout:

They also provide a schematic:

https://files.waveshare.com/upload/6/62/...

I checked the board for shorts or anything obvious and everything seems to be intact - all caps are fine, resistors have resistance and so on. I even touched up some solder joints but that didn't bring any results.

What I need help with is what IC should I probably replace in order to get it back to work? Could be either of the three main ones, but my guess would be it is a PCF8574T:

Could also be a PCF8591T

Or least probable is a realtime clock controller DS3231SN: