Question marks in serial monitor, but baud are the same

[jovialcupdi9]

Hi,
I got my first Arduino. It's nano clone.

I needed to change bootloader to old one.

When i upload example 'digitalreadseries' and nothing is connected to Arduino in series monitor i should only received zeros, right?

I only receive reversed question marks. My baud is in both code and monitor set to 9600. I also tried other values but it never helps.

//-Blink example works fine.
-Fade example turn off and on my build in led but don't fade it.
-analogreadseries works like digitalreadseries

• button example without any cable wired to Arduino lights up build in led constantly

What should I check?

[Grumpy_Mike]

@jovialcupdi9

i should only received zeros, right?

Wrong. Nothing connected to a pin means it is floating and can read anything due to it picking up interference.

Never never post code as a picture it is one of the most useless things you can do.

[Grumpy_Mike]

@jovialcupdi9

Blink example works fine.

What should I check?

You should check the section you posted in. Installation and troubleshooting is NOT for asking questions about your project. If the blink example works then it is the wrong section.
I have moved it to a better place.

[red_car]

As @Grumpy_Mike mentioned, because you have nothing connected to pin 2 then its value is not defined.

If you declare the pin as...

pinMode(pushButton, INPUT_PULLUP);

then it will be HIGH by default, and you should use the push button to pull it to GROUND.

Also...

delay(1);

isn't enough of a delay to stop the monitor from being flooded with output... try

delay(100);  // 0.1 second

Also, if you ever post code make sure you use code tags (this button in the editor </>)... it is much easier for anyone to then debug.