Atari 5200:Bypassing the Switchbox (4-port): Difference between revisions

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(Rewriting procedure, I also found (based on a factory modded 4-port) that removing the large filter cap is completely unnecessary)
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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.
By default, most 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 power and also provides the RF signal to a TV. The switchbox can be a point of failure, and the combining of power and audio/video into one wire can contribute to audio/video interference. In the later 2-port models and a handful of 4-port consoles, a dedicated power jack was added to the console, allowing these consoles to use a conventional manual switchbox.


This guide will walk you through installing a [https://console5.com/store/atari-5200-4-port-powered-switchbox-bypass-modification-kit.html power jack mod kit] ([https://console5.com/wiki/Atari_5200#4-Port_Switchbox_Elimination_Modification documentation]) into your Atari 5200 on a 4-port model to separate the audio/video from your power line.
==Overview==
In a normal 4-port 5200 console, the DC input power that travels through the RF/power cable is filtered out by an inductor labeled L8, which then supplies this DC power to the two 7805 voltage regulators. By removing L8 and injecting input voltage to where L8 connects to the rest of the power circuit, the switchbox can be completely bypassed.  


== Notes ==
== Notes ==
* The included diode is for reverse-polarity protection and isn't necessary but is highly recommended.
* The included diode is for reverse-polarity protection and isn't necessary but is highly recommended.
* The original 4700µF can be used in place of 47µF but will need to be relocated and have it's leads extended. It is recommended to use the new capacitor instead.
* Removing the original 47 or 4700 µF filter capacitor is not necessary, but it can be replaced if desired.
* You do not need to remove the metal RF shielding for this mod.
* You do not need to remove the metal RF shielding for this mod, as all of the power circuitry is outside of the RF shielding.
* This kit uses the original power supply though any 2A, 9–11.5V DC power supply with center positive 5.5 mm outer diameter, 2.5 mm inner diameter plug will work. You may also substitute any power jack of your choosing, such as a 5.5 x 2.1 mm barrel jack wired for center negative polarity so a model 1 Sega Genesis AC adapter may be used.
* This kit uses the original power supply, though any 9–11.5V 2A DC power supply with center positive 5.5 mm outer diameter, 2.5 mm inner diameter plug will work. You may also substitute any power jack of your choosing, such as a 5.5 x 2.1 mm barrel jack wired for center negative polarity so a model 1 Sega Genesis AC adapter may be used.
* While ultimately the attached video cable can be removed, it is recommended to leave it intact in order to test the mod afterwards.
* While the attached video cable can be removed, it is recommended to leave it intact in order to test the mod afterwards.


== Removing Components ==
==Materials and Tools==
===Materials===
* Leaded solder
* 4-port power jack modification kit, available from [https://console5.com/store/atari-5200-4-port-powered-switchbox-bypass-modification-kit.html Console5]
**If not using the kit, gather the following:
**5.5 x 2.5 mm panel mount DC power jack (can be substituted for power jack of your choosing if not using original PSU)
**Hookup wire
**1N4001 diode or equivalent
**0.1 µF ceramic capacitor
**47 µF or 4700 µF 25V electrolytic capacitor (optional)


# 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.
===Tools===
# Remove inductor L8.
* Phillips head screwdriver
* Soldering iron
* Multimeter
* Flush cutters
* Wire stripper
* Multimeter
* Desoldering braid or desoldering gun (optional)


== Mounting Power Jack ==
==Procedure==
 
# Flip over the 5200 console and remove the seven screws securing the shell. Be mindful of the two rearmost screws near the controller storage area, which are shorter than the rest.
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.
# Carefully remove the top shell and set it aside.
 
# Remove the motherboard from the bottom shell. Route the RF/power cable out of the bottom shell and secure it so it does not get in the way.
== Soldering ==
# Snip out or desolder inductor L8, which is located right between the RF/power cable and the RF modulator.
 
#*Optionally, remove capacitor C45 and replace it with a capacitor of the same value. Depending on the motherboard, the footprint underneath it may be different and it may be a large (4700 µF) or small (47 µF) capacitor.
# Solder the non-band side of the diode to the red wire of one of the two included quick-release connectors.
# Locate an area to mount the power jack. It is recommended to place it close by the channel select switch, similar to a 2-port console.
# Solder the band-side of the diode to southern-most via of the inductor you removed (L8).  
#* Some 4-port consoles may have a large square hole near the switch, which is where the power jack on a 2-port console would normally be. This hole may be too large for most panel mount jacks, but a large washer or piece of plastic secured with epoxy behind the hole should be enough to provide extra support.
# Solder the black wire of the same quick-release connector to the northern-most via that was covered by the capacitor you removed (C45).
# Drill a suitable size hole for the power jack and mount the jack to the shell.
# Solder the 47 µF capacitor where the capacitor you removed was. Ensure that you have the correct polarity.
# Solder the cathode (striped end) of a 1N4001 diode to the lower (towards the front) via of inductor L8, then solder the anode to the red wire of one of the quick-release connectors included with the kit.
# 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.
# Solder the black wire of the same quick-release connector to a ground source. The rightmost lead of capacitor C36 or leftmost lead of capacitor C310 are good choices.
# Solder the red wire of the other quick-release connector to the center post of the DC jack.
# Solder a 0.1 µF ceramic capacitor between the center and outer posts of the DC power jack. Ensure that they are not shorted together.
# Solder the last remaining black wire of the quick-release connector to the outer post or shield of the DC jack.
# Solder the other end of the red wire to the center post of the power jack, and the other end of the black wire to the outer post of the power jack.
 
#* If you wish to use a tip negative power supply such as a model 1 Genesis AC adapter, solder the red wire to the outer post of the jack and the black wire to the center post.
== Testing ==
# Reassemble the console to the point where it can be tested. Test the power mod by connecting the RF cable to a regular manual switchbox or coax adapter on your TV, then connect the power supply to the jack you just installed. If the console continues to power on and function normally, the test is complete and the console can be fully reassembled.
 
#*Optionally, the hardwired RF cable can be removed from the motherboard to make future repairs or modifications simpler. If you wish to retain RF output after removing the hardwired cable, a standard RCA cable can be connected to the RCA jack on the motherboard and then routed through the bottom shell.
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.

Revision as of 17:34, 31 March 2023

By default, most 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 power and also provides the RF signal to a TV. The switchbox can be a point of failure, and the combining of power and audio/video into one wire can contribute to audio/video interference. In the later 2-port models and a handful of 4-port consoles, a dedicated power jack was added to the console, allowing these consoles to use a conventional manual switchbox.

Overview

In a normal 4-port 5200 console, the DC input power that travels through the RF/power cable is filtered out by an inductor labeled L8, which then supplies this DC power to the two 7805 voltage regulators. By removing L8 and injecting input voltage to where L8 connects to the rest of the power circuit, the switchbox can be completely bypassed.

Notes

  • The included diode is for reverse-polarity protection and isn't necessary but is highly recommended.
  • Removing the original 47 or 4700 µF filter capacitor is not necessary, but it can be replaced if desired.
  • You do not need to remove the metal RF shielding for this mod, as all of the power circuitry is outside of the RF shielding.
  • This kit uses the original power supply, though any 9–11.5V 2A DC power supply with center positive 5.5 mm outer diameter, 2.5 mm inner diameter plug will work. You may also substitute any power jack of your choosing, such as a 5.5 x 2.1 mm barrel jack wired for center negative polarity so a model 1 Sega Genesis AC adapter may be used.
  • While the attached video cable can be removed, it is recommended to leave it intact in order to test the mod afterwards.

Materials and Tools

Materials

  • Leaded solder
  • 4-port power jack modification kit, available from Console5
    • If not using the kit, gather the following:
    • 5.5 x 2.5 mm panel mount DC power jack (can be substituted for power jack of your choosing if not using original PSU)
    • Hookup wire
    • 1N4001 diode or equivalent
    • 0.1 µF ceramic capacitor
    • 47 µF or 4700 µF 25V electrolytic capacitor (optional)

Tools

  • Phillips head screwdriver
  • Soldering iron
  • Multimeter
  • Flush cutters
  • Wire stripper
  • Multimeter
  • Desoldering braid or desoldering gun (optional)

Procedure

  1. Flip over the 5200 console and remove the seven screws securing the shell. Be mindful of the two rearmost screws near the controller storage area, which are shorter than the rest.
  2. Carefully remove the top shell and set it aside.
  3. Remove the motherboard from the bottom shell. Route the RF/power cable out of the bottom shell and secure it so it does not get in the way.
  4. Snip out or desolder inductor L8, which is located right between the RF/power cable and the RF modulator.
    • Optionally, remove capacitor C45 and replace it with a capacitor of the same value. Depending on the motherboard, the footprint underneath it may be different and it may be a large (4700 µF) or small (47 µF) capacitor.
  5. Locate an area to mount the power jack. It is recommended to place it close by the channel select switch, similar to a 2-port console.
    • Some 4-port consoles may have a large square hole near the switch, which is where the power jack on a 2-port console would normally be. This hole may be too large for most panel mount jacks, but a large washer or piece of plastic secured with epoxy behind the hole should be enough to provide extra support.
  6. Drill a suitable size hole for the power jack and mount the jack to the shell.
  7. Solder the cathode (striped end) of a 1N4001 diode to the lower (towards the front) via of inductor L8, then solder the anode to the red wire of one of the quick-release connectors included with the kit.
  8. Solder the black wire of the same quick-release connector to a ground source. The rightmost lead of capacitor C36 or leftmost lead of capacitor C310 are good choices.
  9. Solder a 0.1 µF ceramic capacitor between the center and outer posts of the DC power jack. Ensure that they are not shorted together.
  10. Solder the other end of the red wire to the center post of the power jack, and the other end of the black wire to the outer post of the power jack.
    • If you wish to use a tip negative power supply such as a model 1 Genesis AC adapter, solder the red wire to the outer post of the jack and the black wire to the center post.
  11. Reassemble the console to the point where it can be tested. Test the power mod by connecting the RF cable to a regular manual switchbox or coax adapter on your TV, then connect the power supply to the jack you just installed. If the console continues to power on and function normally, the test is complete and the console can be fully reassembled.
    • Optionally, the hardwired RF cable can be removed from the motherboard to make future repairs or modifications simpler. If you wish to retain RF output after removing the hardwired cable, a standard RCA cable can be connected to the RCA jack on the motherboard and then routed through the bottom shell.