Master System:General Troubleshooting

If your Master System is having issues, check the below general troubleshooting information for help.

No Power LED

Open the console and check the voltage regulator underneath the metal heatsink with a multimeter. One leg should be ground, one leg should be around 9V, and another leg should be 5V.

• If no leg has around 9V, check your power supply and maybe try a different one.
• If no leg has around 5V, replaces the voltage regulator with a new 7805 voltage regulator.

Black Screen

Open the console and remove the top and bottom RF shielding. Plug the console in and see if it works properly. If it does, likely the issue is that the RF shielding is slightly bent and touching the expansion port, shorting out the pads. Either bend the RF shield away or cover the expansion port pads with electrical tape. This port was never used by official accessories, but aftermarket accessories may be used in that port such as the expansion port BackBit cartridge variant.

Light Gun Issues

The most common issue with a light gun is a broken cable. You can order a replacement Genesis controller cable, use a multimeter to test which wire corresponds to each pin on the connector, and swap the old cable for the new one.

If you have a flash cart, you can boot SMS Light Gun Test.sms from this zip file created by Ben Ryves. This will show the tracked location on-screen, showing if it's present at all or if it's mis-aligned — which generally can be fixed by opening the gun and aligning the sensor module.