Pacific Computer City, Bainaohui Computer City, Ego Digital Plaza and Canton Fair Network are all good choices. The first few are physical, so you need to move your legs and run around to have a look. The last one is online, you just need to move your hands and look at the keyboard. How many second-hand parts do you want? If there are not many, it is better to go to the Guangzhou market and find cheap second-hand accessories and network equipment, because there is more information in the Guangzhou market now, so there is no need to go door to door, and there are sellers in need. This is of course my personal suggestion, and I hope it will help you.