Operating Donkey Kong 3 Test Mode

Pressing and holding the Service Switch will cause the Test Mode menu to be displayed. A flashing icon points to the current test. Momentarily depressing the Service Switch will step to the next test. When the flashing icon is pointing to the desired test, the details of that test can be displayed by pressing and holding the Service Switch. You can return to the test mode menu from within a test by pressing and holding the Service Switch until the menu appears. Return to game mode by selecting the last test "Return to game mode" and pressing and holding the Service Switch until it returns to game play mode.

Erasing Donkey Kong 3 High Scores

Enter Test Mode Following the general test mode operation instructions, put the game into test mode. (Press and hold the Switch Switch until the menu appears). Select the menu item "1-DISTRIBUTIONS" (normally already selected). Press and hold the Service Switch until the distribution screen appears.
Clear Distributions Press P1-Start or P2-Start to clear the distributions. Note the message on the bottom indicates this will also clear the high scores. For the Donkey Kong 3 High Score save kit, this also resets the high scores back to the factory defaults. At this point, the game should have returned to the test mode menu with the next item selected.
Return to Game Play At this point, the game should have returned to the test mode menu with the next item selected. Advance the menu to "4-RETURN TO GAME" by Momentarily depressing the Service Switch will step to the next test. Once the last item is selected, press and hold the Service Switch until it returns to game play mode. At this point the high score table should have the following factor default scores and initials.

Setting Donkey Kong 3 FREE PLAY mode

Enter Test Mode, Select FREE PLAY Following the general test mode operation instructions, put the game into test mode. (Press and hold the Switch Switch until the menu appears). Select the menu item "2-FREE PLAY" by momentarily pressing the service switch. Once selected, Press and hold the Service Switch until the free play screen appears.
Toggle Free play setting Press P1-Start or P2-Start to toggle the current free play setting. For the Donkey Kong 3 High Score save kit, the free play option selected will be saved along with the high scores. Press (and hold) the service switch to return to the test mode menu.

Donkey Kong 3 Monitor tests and diagnostics

Diagnostics Following the general test mode operation instructions, put the game into test mode. (Press and hold the Switch Switch until the menu appears). Select the menu item "3-MONITOR ADJUSTMENT & SELF-TEST" by momentarily pressing the service switch. Once selected, Press and hold the Service Switch until the first diagnostic test screen appears. Press either start button to proceed to the next test. The test screens are shown below for reference.

Individual test screens