Donkey Kong was a hot game in 1981. Nintendo had such a hit the price at our distributor went up $2000 for the first 6 months. If ya had to have one, you had to pay. I know, I bought 2 of them. They were hard to get and made a ton of cash.
These games are a challenge to repair shops. The monitor and power supply were hard to work on. The monitor was a jigsaw puzzle to take apart and put back together. The monitor also had inverted video and sync inputs and ran on 100 volts instead of 115v. The audio amp was built into the monitor instead of the game board.
The power supply was one of the first switching regulated power supplies I ever worked on. It came with custom "hybrid" circuit packs that forced you to deal with authorized distributors to get parts and service. The Japanese used a super glue like product to lock the tiny screws and nuts together creating a fun adventure in stripped Philips head screw removal. This particular repair below had the screw issues and 1 bad hybrid pack that made me install a new generic power supply and re-wire the harness.