Crazy/ random printing errors

Hello,
I'm hoping one of you has some insight to the weirdest problem I have encountered on my printer. My printer has crazy random errors. I have been printing some gears for a kinetic sculpture I am making. 3 of the gears were printing fine but 2 on one side were horribly mangled. Plastic deposited like 1 cm away still in the gear shape! large globs strewn about. I originally thought that it might just be poor adhesion on the one side or some other common problem. Then one of the gears started printing normally. Of course the bottom was still printing correctly, but the top was perfect. The other gears were printing perfectly the whole time so surely it cannot be mechanical. Another gear failed the exact same way about 75% of the way through the print and I stopped it soon after. So I had one gear failing early on, one gear completely failing the whole time, 1 gear fail towards the end, and two gears printing perfectly until I stopped it! I thought it might be my SD card so I got a brand new one and put 2 gears on, this time one printed perfectly and the other one went crazy! I cant explain this at all!

had something similiar recently when my delta just started randomly making spaghetti at the side of the build plate.

cleared and reformatted the sd card and that did the trick.

I think you're on the right track - might be worth getting a new sd card reader/writer for your computer.

What printer are you using ?
could be the card reader on the printer itself.

But I'd definitely lean towards a corrupted g-code file.