I found PCB from the classic 2600 JR. It was forcefully removed from the case maybe using a hammer. The PCB is bent, some parts torn out and missing switches.
PCB was cracked and several traces were broken. I repaired them, but the game didn’t start. Sometimes I noticed some video starting, but only for a few frames. I checked all connections using an oscilloscope and found that the CPU address pin (A7, maybe) is floating. I removed the chip and everything become clear:
Very interesting- the chip body is broken, but the crystal is OK. Only ONE leg disconnected.
The rest of the story is very simple: ordered some cheap from China, received a fake one, opened a dispute, and received money back. Then I ordered some other and the system started up.