This is the video/audio chip at the heart of the Commodore VIC-20. Unfortunately, it is also one of the most common components to fail. I have replacements available. These have been pulled from scrap VIC-20 boards, but have been tested as good in a working VIC-20 board. This is the NTSC version.
Note about stock: I have limited stock ready to ship, but I have more that can be tested. So if you see that it is out-of-stock, just wait a few days and check back as I will likely have more.