- Return it, get your money back
- Or Toss it and buy a new GPU
- Never buy a used GPU again
All of my GPUs have been used! They're great value! Your first two points are good advice for OPs case though
As for OPs question, it's not unusual to have blank spots on the PCB even if it looks like something is supposed to be there. So I don't expect something to actually be missing. Nothing in your pics stand out to me.
These RX 570 and 580s are notorious for being mining cards, so it's possible it has a mining BIOS on it and that's why it doesn't output. Depending on how much you paid for it you could just write it off and get something better, but reflashing it to a stock BIOS is free with a little know how and help from TPU.. if that turns out to be the issue. Or it could just be completely dead
This is where my knowledge ends on flashing though. There are others here that will be able to help properly identify your model and suggest a BIOS to try and maybe even walk you through how to do it. Knowing it's a Sapphire and getting a closer pic of the memory modules will be helpful