Outerworld Arcade

Atari Sprint 2 (1976)
Power Supply Repair

 

Atari's early black and white games all had their power supply circuitry, main game circuitry, and sound circuitry integrated on one board. If your game on power up makes a humming noise from the speakers and shows nothing on the display, it's likely the game's ICs are not getting the +5v DC that they need to operate. Here's how to test the power supply of Sprint 2 (and possibly other Atari games from this era).

Atari Sprint 2 Power Supply +5v Test PointsThe image to the left shows the test points for the Sprint 2 power supply. Click it for a larger view of the image.

Place multimeter leads on each of the RED points to test AC input on board. The multimeter should read around +16.5v AC. If it is dramatically different (mine is 17.5v AC), check the edge connector and cabinet wiring.

Place black multimeter lead on a DC ground point (a 7400 series IC is a good option)

-then-

Place red lead of the multimeter on each of the YELLOW points. These should measure about +10v DC.

Place the red lead of the multimeter on the BLUE point. This point should read +5v DC. If it doesn't the L323 could be bad.

Please note: a short somewhere on the board can cause the readings at the YELLOW and BLUE points to be off while the components of the power supply are in fact fine - this is currently happening on one of my Sprint 2 pcbs.