Atari 5200:Bypassing the Switchbox (4-port)

By default, the 4-port Atari 5200 models have a single permanently-attached RF video cable that also doubles as the power cable for the console. This configuration requires a special switchbox made specifically for the Atari 5200 which provides the power and also provides the RF signal to your TV. The switchbox can be a point of failure and likely the combining of power and audio/video into one wire contributes to audio/video interference. In the later 2-port models, a dedicated power jack was added to the console.

This guide will walk you through installing a power jack mod kit (documentation) into your Atari 5200 on a 4-port model to separate the audio/video from your power line.

Removing Components

 * 1) Remove capacitor C45. Depending on your motherboard, the footprint underneath it may be different and it may be a large (4700µF) or small (47µF) capacitor.
 * 2) Remove inductor L8.

Mounting Power Jack
Choose where you'd like the power jack. The most obvious choice is to drill where the power jack is on the later models - right next to the hole for the channel switch in the back-right of the console. Some 4-port models have an existing hole in this spot due to the factory putting the motherboard in a newer shell designed for the later 2-port revision. However, sometimes this hole is too large for the power jack you have, so you may need to use a large washer or use epoxy to attach a piece of plastic to a shape large enough to cover the existing hole in the case and drill a hole through it to fit the power jack.

Soldering

 * 1) Solder the non-band side of the diode to the red wire of one of the two included quick-release connectors.
 * 2) Solder the band-side of the diode to southern-most via of the inductor you removed (L8).
 * 3) Solder the black wire of the same quick-release connector to the northern-most via that was covered by the capacitor you removed (C45).
 * 4) Solder the 47 µF capacitor where the capacitor you removed was. Ensure that you have the correct polarity.
 * 5) Solder the 0.1 µF capacitor between the center post and outer post of the DC jack. You may want to check that there is no continuity between the two.
 * 6) Solder the red wire of the other quick-release connector to the center post of the DC jack.
 * 7) Solder the last remaining black wire of the quick-release connector to the outer post or shield of the DC jack.

Testing
Test the functionality of the power mod by plugging the RF cable into a standard switchbox and hooking it up to a TV and making sure you can play it. Alternatively, you can use the RCA jack on the motherboard to get an RF signal.
 * (Optional) Remove the RF video cable. If you are planning to do another mod, such as a RGB or composite video mod, you can remove the attached RF cable by bending open the metal tabs holding the cable in place and then desoldering the cable.