/vr/ - Retro Games

I just got pic related.
Console works great, but the side buttons on both controllers are not responsive. I also know nothing specific about this problem.
Is this common? How do I fix this? Is it easy to fix, or am I replacing these?

I do have a good electrical skillset.

Help me out /vr/.
I just pulled a bag full of 2nd gen games from an estate sale. It looks like it's all Atari and Coleco games.
These games are all about as old as I am, and I know almost nothing about them aside from what is on the lables. I haven't even touched either system for about 25 years.

My real problem is, there were no systems in the lot, only loose cartridges. I can't play them and I want to go about this in a smart way.

How can I include these games in my collection? Are there any good console clones or anyone still refurbishing these things? Are there any good cases available that work with these carts?

I'm not really looking for a project here. I'd rather just buy something that works and play my new games!