Atari 2600 Composite mod help

[Zeewestuh]

I tried searching numerous topics before making this post. Most contain comparisons and "I just sent mine to xxxx to be modded."

 

Anyways, I tried composite modding my Darth Vader 2600 last night using this schematic:

 

 

and this guide since I assume this is the exact same circuit (minus the 75 ohm resistor for the tv):

http://www.vintagegamingandmore.com/installation-guide-4switch/

 

but I get the exact same result as this guy from this page:

 

http://www.cheeptech.com/2600mods/2600mods.html#themods

"All I got was a brief "blink" on the NTSC monitor when I powered up, then black, so no test results are available."

 

 

That's what happens to me when following that guide with that schematic. Is there something being left out? I notice in the guide some resistors are also removed that are no mentioned in the installation. Does this schematic work for the 2600?

 

Are there any other installation guides that cover everything necessary and does this 'video driver' also work on a 2600? Thanks.

[thecrypticodor]

 

If you can post some pictures of your mod board and your Atari it would make troubleshooting your problem a lot easier. When you left out the 75 ohm you didn't just connect ground to the emitter of your 2N2222 did you?

 

Here's a better diagram of the circuit you are trying to build.

 

[Zeewestuh]

Figured it out, the guide says to remove Q202, but it can be Q201. Well I saw the board and Saw Q201 and removed it >_>. Not realizing it was in the wrong area. Worked fine after I replaced the transistor and removed the proper one and all was well. Thanks.

[Atari-Collector]

I did my 2600 Jr with that mod minus the 75 ohm resistor and a 2N3904 transistor. first build didn't work, second was fine using a different transistor, so the first failed due to a weak transistor. Luckily I have about ten 2n3904's in my parts box since they are super cheap.

[+xucaen]

I just ordered the mod kit from vintagegamingandmore, I plan on installing it to a sixer. This will probably be the most complicated solder job I have ever done.

Edited May 8, 2014 by xucaen

[Centurion13]

Hate to practice thread necromancy, but I have been approached by a guy who wants ALL his Atari 2600s refitted for A/V RCA connections.

 

I have the circuit diagram and am no slouch with a soldering iron, but from what I have seen in this column, that circuit deals only with the video signal.

 

What connections are necessary for the audio portion? Or is it simply taken right off the chip? I see connections leading into and out of the board for the audio but do not see anything on the circuit schematic dealing with this.

 

Regards,

 

Cent13