I think I've messed with it too much and did something unhealthy and fried the **** out of it.
At one point it was very hot on the back.
I can describe it as hot as a mcdonalds pie, probably even more.
It fails to upload sketches (says some programmer is not responding)
and when I press the cute little restart button, the green LED doesn't do its blink anymore.
Which I assume means the bootloader ATmega16U2 chip is probably malfunctioning.
Since I'm lucky that my multimeter works, I measured the voltages
The 5V pin gives 4.90-4.91
The 3.3V pin gives 3.31
The TX gives 4.72-4.77
The RX gives 4.88
Should I forget about it?
You can try the loopback test. If that works, it's the 328 and you can replace it with a new one (with optiboot preloaded if you don't have the option to burn a mew bootloader); this assumes you have dip verdion. If it does not work, it's the 16U2.
spycatcher2k:
Unless you have SMD rework equipment, or know someone who does, there is little chance of recovery - New 16u2, new 328 (Possibly) - new mosfet, new opamp.
Thanks for clearing that out, mate you too sterr.
I live in country where Arduino means only "cow milking".
No boards, no parts no nothing.
So I'll just perhaps probably eventually order more arduinos in the imminent future.