missing parts from M audio av30 monitors

Hi, I'm sharing my problem. I recently found some AV30 monitors for repair at a secondhand market, which interested me. I set myself the challenge of trying to repair them, but when I opened the main monitor, I noticed it was missing certain parts. I was wondering if any of you know what's missing so I can try to find them and revive them.

P.S. The secondary monitor is in perfect condition; the main one is the one that's damaged.

Thanks in advance!