In part 1 I cleaned and repaired my Atari 2600 Jnr; the result looked really good but it still needed an old TV with a tuner to use. So my next task was to do a composite mod; this is well documented on various sites. The circuit is simple but I decided to buy a pre-made PCB from eBay. I followed the guide on The Future was 8 Bit (you can also buy the PCB from them), the provided series of photos made it really straight forward.
The mod involves removing a number of components from the main board, so you will need reasonable de-soldering skills if you are going to attempt this yourself.
For reference my Atari 2600 jnr is a PAL edition and is shown in the photo above; there appear to be several versions of the PCB.
You need to remove the following:
- TV Encoder (metal box) – I also removed the TV jack as a single unit to keep them all together
- L8 – Inductor (red thing with copped wire wrapped around it)
- Q4 – Transistor (black round thing with three legs)
- R56 – Resistor
After removing the components I gave the board a good clean with isopropanol to remove the residue from the flux that I added to aid de-soldering.
Next step was to following the guide and solder various new wired to the mod PCB.
Basically, this involves connecting 5v, ground and video connections to points freed-up by the removed components. The board I have doesn’t include the sound connection so I wired this directly to the output jacks, as shown in the photo.
I chose to add female RCA jacks to the case using a stepped hole drill, this is obviously destructive and in retrospect I might choose to use a cable dangling out of the open TV connector socket if I do another…. (although the connectors do look good).
Connecting to the jacks is easy:
- Connect all grounds to the ground on the board (outer casing of the RCA connectors)
- Video out to the centre pin of the video jack (usually yellow)
- Audio out to the centre pins of both audio jacks (usually red and white)
To make future work easier I included a 3 pin connector between the mod board and the case connectors to allow the top to be disconnected from the bottom easily.
The final thing was a dab of hot glue to secure the mod board and cables to the motherboard and to close the case.
With everything finished I tested the mod with a quick game of Jungle Hunt. Interestingly, I tried the other games that I have and didn’t have an issue with the dodgy cartridge connection, everything worked without a fault ?
Now I need to get some new controllers and cartridges 🙂