Any solution for the colour bleed caused by the composite mod?

[rednakes1]

Ugh... I'm starting to regret doing a composite mod on my 4-switch woody 2600. I installed the kit from vintagegamingandmore.com (the two resistors and one transistor), but the colours bleed, and in certain games like Ms. Pacman the audio causes a faint wavy vertical line down the center of the screen to appear.

 

I've tried searching old posts but there doesn't seem to be a solution to my problem. I adjusted the colour potentiometer but that doesn't stop the colour bleed. This is very obvious in Jr. Pacman and also the tank in Battlezone.

 

I didn't have these issues with the RF connection.

 

Any help?

 

EDIT: None of my TVs support S-Video so an S-Video mod is out of the question. Also I didn't remove the big shiny RF box but I did remove the little board attached to it (which had the pins attached to the main board).

Edited November 2, 2016 by rednakes1

[Keatah]

I hate it when the RF modulator gets broken because of piss poor instructions. Totally not professional - telling a customer to bend and break things.

[Keatah]

I know it doesn't help the OP. But I believe that these mods require that the VCS be in good health, good capacitors, no rust or corrosion or contaminants present. Proper routing of the wires away from noisy circuits. No out of tolerance parts. Rock solid power supply and regulator. A lot of things need to go right that the seller of the mod doesn't mention.

 

And again, busting up the RF modulator board is just.. just.. I don't know WHAT it is. Plain old wrong.

[rednakes1]

Here's an attachment showing the colour bleed problem I'm talking about, as seen in Jr. Pacman.

 

I did try changing the A/V cables and tried a different TV input but that made no difference.

[rednakes1]

I know it doesn't help the OP. But I believe that these mods require that the VCS be in good health, good capacitors, no rust or corrosion or contaminants present. Proper routing of the wires away from noisy circuits. No out of tolerance parts. Rock solid power supply and regulator. A lot of things need to go right that the seller of the mod doesn't mention.

 

And again, busting up the RF modulator board is just.. just.. I don't know WHAT it is. Plain old wrong.

 

Do you know of an effective way to remove the RF box? I tried to desolder it but it is very difficult. Not sure if it matters anyway since it's disconnected from the 5 pins.

[Keatah]

If it's disconnected, then just let it be.

 

The way I'd take it out of circuit is by desoldering the connector entirely. Then setting aside the connector for possible future use.

 

Removing the box will be hard unless you have something like a solder plate with a lot of thermal capacity.

Edited November 2, 2016 by Keatah

[Osgeld]

Remove c215 see if that helps, if you look where you attached the audio connection the row of components below that it should be in that row on the end in the right

 

Just lift one leg so if you want to put it back you can

 

Edit another view to find it is it should be the first component to the left of the 5 pins of the rf box

Edited November 2, 2016 by Osgeld

[rednakes1]

If it's disconnected, then just let it be.

The way I'd take it out of circuit is by desoldering the connector entirely. Then setting aside the connector for possible future use.

Removing the box will be hard unless you have something like a solder plate with a lot of thermal capacity.

I did desolder the pins off the main board but then got impatient and cut off the RF circuit board. Oh well.

[Osgeld]

Btw if you want an rf box I got a couple from 4 switchers, but I find taking C215 out of circuit cuts a ton of bleed out

[rednakes1]

Remove c215 see if that helps, if you look where you attached the audio connection the row of components below that it should be in that row on the end in the right

 

Just lift one leg so if you want to put it back you can

 

Edit another view to find it is it should be the first component to the left of the 5 pins of the rf box

 

Thanks, I do see C215. I'll try it tonight. I'll attach a photo for reference, just to show my wiring in that region.

[Osgeld]

Must be nice ever board I have worked on they put the firm designators under the components lol

[rednakes1]

Must be nice ever board I have worked on they put the firm designators under the components lol

 

Yeah it's a Rev 13 board ... BTW if you have a spare bottom casing for a 4-switch, let me know, I messed up the drilling on mine and had to re-drill because the holes were too close (that's what I get for printing the template from Longhorn Engineer site and not measuring on my own).

[rednakes1]

Is there any reason to remove R222 (15K resistor)? I noticed a couple of guides where they removed it along with C215.

[Osgeld]

Off the top of my head I don't remember, I don't use the transistor mod I make my own amp boards so I loosely follow mod guides

 

And no I don't have any spare case parts at the moment, just an rf modulator out of a 4 switch I am av modding

 

Lesson of the day, trust but verify printing can scale templates weird

Edited November 2, 2016 by Osgeld

[rednakes1]

Just tried it during my lunch break. No, removing C215 doesn't help. Still getting the ghosting/bleeding. I'm seeing faint vertical bars all across the screen now but that may just be coincidence or some kind of interference on my CRT TV.

[Osgeld]

well poo

[rednakes1]

I double-checked the resistors on the mod board, and they are placed in the correct spots (2.2K and 3.3K). Can't think of anything else.

 

I did notice I have a ground wire going to the RF connector which has become loose, but when it's held in place there's no improvement. I'll re-solder it tonight but I doubt that's a factor.

[hizzy]

Does this always happen when you do a composite mod?

 

Thanks!

[rednakes1]

Does this always happen when you do a composite mod?

 

Thanks!

This is the first one I've ever done on a 2600. I did one on a Colecovision and it worked out great, using same cable and TV.

[Keatah]

I would think it's a hit or miss depending how everything comes together and matches - like I said in post #3.

 

I also believe that whatever minor OOT flaws present in the original machine are going to get amplified and highlighted by such mods.

[rednakes1]

I would think it's a hit or miss depending how everything comes together and matches - like I said in post #3.

 

I also believe that whatever minor OOT flaws present in the original machine are going to get amplified and highlighted by such mods.

Seems like it In the meantime I've contacted the seller of the mod for help.

 

I found a similar thread to this one, here: http://atariage.com/forums/topic/254792-atari-2600-composite-av-mod-help/

He had success with 2 of 3 systems.

[rednakes1]

Here's the vertical flickering line I see occasionally when playing Ms Pacman now. It happens usually when the audio is playing or right when a new turn starts.

 

EDIT: It's the line down the middle

Edited November 3, 2016 by rednakes1

[rednakes1]

Okay I'm talking to myself

 

I wonder if the Ms Pacman video issue shown in my previous post is caused by DC offset (noise) on the audio line? Someone in another thread a few months ago had a similar issue in a different game and said that disconnecting the mod's audio wire stopped the vertical line from appearing at the center - So the sound had caused it.. Maybe a capacitor is needed in the connection, right before the audio line is tapped to the output jacks?

 

Based on the 2600 schematic (attached) the audio for the mod is connected at the junction of R206 and C208, which is shown at the right side of the pic (R206 is the 18K resistor). Instead of this location, how about connecting the wire after the 820 pF capacitor, before it feeds to R209 (1.8K resistor on the left)?

 

Also note that the transistor shown in the schematic was already removed for the mod.

 

Can someone perhaps comment on this? Maybe I'm talking nonsense.

Edited November 3, 2016 by rednakes1

[atariactionman]

I know this sounds daft but double check your av connections. My modded 7800 used to play me up continuously, until I bought a gold plated phono video connector. It used to picture jump when loud audio sounds played and the screen would roll and artifacts would appear. Now it plays perfect. Give a better quality cable a try. Very best of luck to you, I know how annoying this problem can be.

[rednakes1]

I know this sounds daft but double check your av connections. My modded 7800 used to play me up continuously, until I bought a gold plated phono video connector. It used to picture jump when loud audio sounds played and the screen would roll and artifacts would appear. Now it plays perfect. Give a better quality cable a try. Very best of luck to you, I know how annoying this problem can be.

Interesting, I'll try to give that a shot in the future. I did order a 4-pole TRRS jack and cable recently so I'll give that a try as well.

 

I think my biggest issue right now is that vertical line in Ms Pacman during audio; I don't notice it happen in other games right now (although I thought it did, I may have been mistaken). I think the bleeding problem is most annoying in Jr Pacman only, and I can live with the small bleeding in other games that I've tried so far

Edited November 3, 2016 by rednakes1