Chosen Solution
Hi - The left USB port on my MacBook Pro only works to charge devices, it won’t recognize the device. The right USB port doesn’t work at all. It’s a secondhand laptop from craigslist and the seller said both ports worked before the sale. I already did an SMC reset and PRAM reset, nothing has changed. What should I try next? Edit: I realized my use of right and left is confusing. Both ports are on the left edge of the laptop. The port closest to the SD card slot is the “right” one that isn’t working at all. The other USB port is what I called the “left” one and only charges.
OK, with the correction we now know you have a Unibody model (most people use Top or Bottom to describe the ports). In this model both ports are part of the main logic board
Sadly, your system logic board needs repairs or it may need replacement! Both efforts would add costs! I think is smarter to return the system and get your money back.
