The original jack briefly shorts the power supply to ground each time you insert or remove the plug, so that's another good reason to replace it.
Another mod I added which you can't see is a front 9 pin joystick connector hidden under the the lip of the console, a bit like how the 5200 and 7800 had theirs, but this port is connected to just the direction, action buttons and ground of the left controller. The other 3 pins I intend to connect to the action button, up and down of the second joystick port, so when I make my arcade stick, I can plug it in to this front port and have 4 action buttons for Stargate (Defender II), and the frontal port still be compatible with the standard Atari joystick at the same time, and still have the back ports for things like paddles.
Very clever! Stargate is one of the games I had as a kid, but actually I never used the second joystick: I only had two proline joysticks at the time and you can't easily press the button or move the stick on those unless you keep them in your hand...
- Quon likes this