5200 S-Video Mod Success Story

[ruthsarian]

I picked up a 5200 s-video mod board from ElectronicSentimentalities off eBay and installed it over the last couple weekends into my 4-port 5200. I first installed the power mod from console5.com since the video mod bypasses the RF module and that's where the power comes in on the 5200.

 

I decided to mount the video and audio ports on the little door covering the accessory edge connector. To make life easier (in the long run), I made the audio and video cables pluggable to the video mod board. The video cables running from the mod board to the A/V ports came out of an old custom mixer that was being thrown away at work. The cables are shielded and carry a red, black, and bare wire. I just used the red and black wires, so I used three of these shielded cables (composite, chroma, and luma). These cables were very stiff and difficult to shape/direct. If I were to do this again I'd use much more flexible cable.

 

I first tried using female machine pin headers to connect to the GTIA that way if the GTIA goes bad or I need to pull the mod board I don't have to break out a soldering iron. Unfortunately the connection, especially on pin 31 which is all by itself, was problematic. In the end I just soldered the wires to the GTIA pins. The cable from the GITA to the mod board is a little longer than it needed to be, but I wanted a little slack. The direction say you should keep the wires as short as possible to reduce the chance for interference with the signal. I'm not sure if the extra length hurts the signal at all, but it looks good to me.

 

I pulled the RF module, the PCB-mounted RCA jack, and a few other components in that area that are no longer necessary with the video mod in place. Early on I was thinking I might try mounting the mod board there and wanted to free up some space, but ultimately decided to mount it where everyone else who has done this mod mounted it. I may try mounting it there in the future, but I'll need to make a shielded cable to carry the video signals from the GTIA to the mod board. Perhaps something similar to what's there now, just wrapped in copper or aluminum foil tape.

 

Audio taps into resistor R50 and for ground I tap into a ground trace shared by R14, R12, and C18. I made a little plug for this cable as well. The mod kit comes with two RCA jacks even though the 5200 does not do stereo sound. I installed both RCA jacks, connected the audio wires to one RCA jack, then wired the second RCA jack to the first. The sound works great.

 

The mod board needs 5 volts so I found a filled via in the middle of the board that was on the 5v rail, sucked out the solder, and stuck a pin in there. I did the same for a ground point in the middle of the board.

 

I've mounted the board over the ANTIC and U1 and U4 chips. Since the ANTIC can get fairly hot, I put a couple small heat sinks on top and mounted the video mod board to the heat sinks using some double-sided tape. And since the board is between the ANTIC and U1/U4 chips, there's room for airflow underneath to (hopefully) not trap hot air and create problems.

 

With everything connected up I plugged it into my TV, fired it up, and amazingly it worked! The composite video signal is a hundred times better than the RF signal. Unfortunately I don't have s-video in on my TV, but I did have an S-Video USB stick and tried it out on my computer. The s-video signal is 100 times better than the composite signal. The image is crystal clear. Very cool!

 

Now for some pictures!

 

Here's an example of what it looked like before the mod. I used Popeye because that's the game that I've found creates the most noise/distortion.

 

And here's the composite signal on my TV after the mod:

 

Here's a view of the entire, modded PCB:

 

Here's the wired-up A/V harness:

 

And a close-up of the A/V jacks:

 

A close-up of where I tap into the audio on the PCB:

 

And a close-up of where I pulled 5 volts for the mod board. The ground pin is in the back.

[TheDevil'sCompass]

Looks great! The difference is night and day.

[chavert]

congratulation

[Coldheat]

So the instructions on the web site says to attached a 1uf capacitor for the sound output. Did you do this? If so where did you place it?[/size]

4. Locate the correct sound pickup point.
A typical Atari sound circuit is shown on the included POKEY chip diagram. Locate a spot on the board that is tied to pin 37, which will be where the 1uf capacitor is attached for the sound output connection (this will be done later.)

 

Use the above pin-out for correct wiring to mod board. Use the included 1uF capacitor for the audio out connection with the negative end connected to the center of the RCA jack and the positive soldered to the audio point you found earlier on the Atari board. Plug the GTIA connector into the mod board and make sure the pin connections are correct.

Edited November 10, 2016 by Coldheat

[ruthsarian]

So the instructions on the web site says to attached a 1uf capacitor for the sound output. Did you do this? If so where did you place it?

 

 

I did. I attached a wire to R50 (second to last pic) and then attached the capacitor to that wire. If you look at the first image that shows the whole board, you can follow the white wire from R50 to this lump underneath some yellow heat shrink tubing. That lump is the capacitor. I didn't want to solder the capacitor directly to the POKEY (no reason you can't do that) and found R50 on my board (early 4-port) is the 1k resistor in the diagram. I added the wire from R50 so I'd have some flexibility in moving the wire rather than just soldering a capacitor leg right to the board. I could have put the cap right on the RCA jack instead, but I didn't think ahead and had already wired the jack up at that point. And I could have perhaps crimped the female Dupont connector pin directly to the cap's leg, but I felt more comfortable adding a couple inches of wire between the leg and the connector. So what I did works, but I probably made it more complicated than it needed to be.

[Coldheat]

 

I did. I attached a wire to R50 (second to last pic) and then attached the capacitor to that wire. If you look at the first image that shows the whole board, you can follow the white wire from R50 to this lump underneath some yellow heat shrink tubing. That lump is the capacitor. I didn't want to solder the capacitor directly to the POKEY (no reason you can't do that) and found R50 on my board (early 4-port) is the 1k resistor in the diagram. I added the wire from R50 so I'd have some flexibility in moving the wire rather than just soldering a capacitor leg right to the board. I could have put the cap right on the RCA jack instead, but I didn't think ahead and had already wired the jack up at that point. And I could have perhaps crimped the female Dupont connector pin directly to the cap's leg, but I felt more comfortable adding a couple inches of wire between the leg and the connector. So what I did works, but I probably made it more complicated than it needed to be.

 

Ok thanks. I see it now. I am planing to do mine in the next day or so. This helps a lot since there is not a lot on the net that shows details like this.

[+-^CrossBow^-]

 

Ok thanks. I see it now. I am planing to do mine in the next day or so. This helps a lot since there is not a lot on the net that shows details like this.

 

It might not help, but when I modded mine about 3 years ago I took some pretty decent pics of the work. On mine, I attached the capacitor directly at the RCA connections and you can just barely make it out in one of the pics.

 

https://www.facebook.com/media/set/?set=a.10201868503891591.1073741829.1153072122&type=3

[Coldheat]

I finally got the mod installed. At first I was getting a solid yellow screen. I doubled check all my connections and found nothing connected wrong. I still did not work so I did a continuity check and thought I may have a short on the 5 volt line to ground. So I moved the 5 volt line to another spot on the board and tried again with no luck.

I pulled the wires from the S-video and re-soldered everything and it still did not work. I figured I fried the board. One last ditch effort I removed the TIA chip and re inserted it and it Worked!!!!

Thanks for the tips and the screen shots. Crossbow your FB page also helped.

 

 

 

 

Edited November 15, 2016 by Coldheat

[+-^CrossBow^-]

I finally got the mod installed. At first I was getting a solid yellow screen. I doubled check all my connections and found nothing connected wrong. I still did not work so I did a continuity check and thought I may have a short on the 5 volt line to ground. So I moved the 5 volt line to another spot on the board and tried again with no luck.

 

I pulled the wires from the S-video and re-soldered everything and it still did not work. I figured I fried the board. One last ditch effort I removed the TIA chip and re inserted it and it Worked!!!!

 

Thanks for the tips and the screen shots. Crossbow your FB page also helped.

 

IMG_0030_zpskt3jdx6b.JPG

 

 

IMG_0030_zpskt3jdx6b.JPG

Where do you have pin 31 actually soldered from off the GTIA? I'm asking because in the photo above it looks like you have pin 26 through that hole? If you look on mine in the pics I posted earlier, you will see where I have a small wire connecting pin 31 off the GTIA to that point. Just making sure...?

Where do you have pin 31 actually soldered from off the GTIA? I'm asking because in the photo above it looks like you have pin 26 through that hole? If you look on mine in the pics I posted earlier, you will see where I have a small wire connecting pin 31 off the GTIA to that point. Just making sure...?

Edited November 15, 2016 by -^Cro§Bow^-

[Coldheat]

 

 

IMG_0030_zpskt3jdx6b.JPG

 

Where do you have pin 31 actually soldered from off the GTIA? I'm asking because in the photo above it looks like you have pin 26 through that hole? If you look on mine in the pics I posted earlier, you will see where I have a small wire connecting pin 31 off the GTIA to that point. Just making sure...?

Where do you have pin 31 actually soldered from off the GTIA? I'm asking because in the photo above it looks like you have pin 26 through that hole? If you look on mine in the pics I posted earlier, you will see where I have a small wire connecting pin 31 off the GTIA to that point. Just making sure...?

 

 

Sorry I should have explained that. I soldered a short wire and ran it underneath then up through the board. So yeah it does look like I soldered pin 26.

[Omega-TI]

 

Here's an example of what it looked like before the mod. I used Popeye because that's the game that I've found creates the most noise/distortion.

5200_before.jpg

 

And here's the composite signal on my TV after the mod:

5200_after.jpg

 

 

Dang good post! You sold me! It's now on my list of "must do projects".

It was a project I was 'strongly considering', but after coming across your old post, man that was IT!

Before & After - what a difference.

[+-^CrossBow^-]

 

Dang good post! You sold me! It's now on my list of "must do projects".

It was a project I was 'strongly considering', but after coming across your old post, man that was IT!

Before & After - what a difference.

 

if you checked the link I also posted above, I have several before and after comparison shots as well. Most of mine are all up close to show specific detail differences. But yeah! The 5200 s-video modification is IMO, the best one I've seen as far as what a clear difference there is to be had in doing it.