Basic Atari vector troubleshooting process:
- Disconnect the monitor for now. Keep it disconnected until instructed otherwise below.
- Test power voltages. Get a DMM if you don't have one, you will need it. This is not optional. Buy one. Check the 5V DC on the game board, using the labeled 5V test point and any GND test point on the game board. Adjust using the pot on the AR board so it is exactly 5.00V DC on the game board.
- Check the AC ripple on the output of the power brick. This is measured on the 10.3V test point of the AR. Put DMM into *AC* volts mode (not DC), and measure the AC voltage on the 10.3V test point, using the GND test point on the AR, with the game board powered. If it is less than 400mV, you are fine. If it's above that, it's a problem. Post here and let us know.
- If the above voltages are ok, boot directly into test mode. Keep the monitor still disconnected for this step. This is done by powering the cab up with the test switch (inside the door) already turned on. This will force self-test to run, and generate the test result screen, which you won't see, but that's ok. Listen to hear any RAM error beep codes. (See the Ast Deluxe manual for details about RAM errors.)
- If self-test passes (which is indicated by a single quick high beep), next step is to test the XY voltages on the game board. This is done by measuring 4 voltages: The DC voltage on the XOUT and YOUT test points on the game board (they are labeled, near the pots). Set both pots to the center of their range. Then measure the AC voltage on both XOUT and YOUT. If XOUT and YOUT DC are between -2V and +2V, you are ok. If XOUT and YOUT AC are between 1.5 and 3.5V, you are ok. If either DC voltage is outside of the -2 to +2V range, or either AC voltage is zero, the game board has a problem, and you do not want to connect the monitor. Post here if this is the case.
- If the XY voltages test ok, connect the monitor, and boot into test mode again. You should see a crosshatch pattern on the screen. See if there are any ROM error codes (see the manual for details.) If there are, do not take the board out of test mode. You will need to fix the ROM errors first.
Here is the manual if you need it. See the section about Self-Test:
If you have questions (which you should), post them here.