icemanxp300 Posted October 13, 2016 Share Posted October 13, 2016 So I got this Atari that while it worked it had poor video. It had lots of rust and appears to have suffered water damage. So while I was cleaning it up I forgot to discharge the power and I sparked the power connector. Not sure if that is the problem or not. I reflowed the power connector and removed the rf box and installed a composite mod. This was my first attempt at the mod and I figured it was a good system to play around on. It came out real nice but below is the wavy screen I get. It however goes away after a few seconds. I pulled all 3 chips and sprayed deoxit in the mounts and sanded the pins and put them back in, so I don't think the chips are the problem. I actually sprayed deoxit everywhere as the board was really bad from water damage. Ideas? Do I need a new power port or something else get damaged? Yes I just realized I forgot to put the dumb shield on and my red wire will likely be in my way. new pics from switching board ... Quote Link to comment Share on other sites More sharing options...
iesposta Posted October 14, 2016 Share Posted October 14, 2016 Does not need the shield, unless the Atari is interfering with another device. (Also you removed the RF so it is not even radiating the old channel 2/3 signal.) Do you mean it sparked when you plugged the power jack in? Most all my old ones spark, never killed one that way. If you don't have other chips to troubleshoot, I can only suggest replacing the .22uF capacitor nearest the 5V regulator in the lower left. Then or at the same time, replacing the 5V regulator. Console5 dot com sells those parts, as well as a $10 2600 refurbish parts kit. Quote Link to comment Share on other sites More sharing options...
icemanxp300 Posted October 14, 2016 Author Share Posted October 14, 2016 When I took the shielding off initially while I did have the Atari disconnected from power it was still charged. I forgot to power on and off while unplugged. What happened was the shielding was rusted so bad to the board I had to pry it off and when I used the screwdriver to pry the shielding off I touched the solder joints to the power jack and it sparked. Something is. def. weird because I had a few times where the audio did not come in right away and now after messing w/it more swapping out all 3 chips and reflowing all the cartridge slot pins it now has no sound at all. So I swapped out all 3 chips 1 at a time and had same results from a working system, I really do not believe the chips are the problem and now I have no audio which kind of really irks me. Quote Link to comment Share on other sites More sharing options...
icemanxp300 Posted October 14, 2016 Author Share Posted October 14, 2016 Well SOAB it's the mod "my install to be exact". I just swapped the mod to a different board and same thing! Quote Link to comment Share on other sites More sharing options...
icemanxp300 Posted October 14, 2016 Author Share Posted October 14, 2016 Well in case you don't know those pads on top and bottom of the old rf spots are not connected from top to bottom of pcb LOL. I did not have the ground or video connected properly, they went to empty pads. I'm surprised it was working at all. The only thing is I fried that damn transistor. It is a Motorola 2N3904 Transistor. So unless it is the same as the on board one I removed which is a 2N3563 I need to get another transistor. I have video going into it now but none coming out. Continuity shows no video output even though the continuity checks to all pins of the transistor, just not traveling through it now, even when powered on. Quote Link to comment Share on other sites More sharing options...
icemanxp300 Posted October 14, 2016 Author Share Posted October 14, 2016 It's fixed I swapped the transistor out I fried lol. Basically I did not have the ground or video soldered good. I soldered them to pads that went nowhere LOL. Guess that's what I get for assuming the pads were connected. Quote Link to comment Share on other sites More sharing options...
icemanxp300 Posted October 15, 2016 Author Share Posted October 15, 2016 Ok So I have made a diagram for this mod in which case you don't even need an adapter board. All you need to do is mount the new transistor to the old transistors spot, cut a few traces and run a few wires. You then use the old r209 spot for either the 2.2k or the 3.3k and use the 2 holes left over from the old rf jack that are not used to mount the 2nd resistor again rewiring as needed. After I do some pin traces on them to see I will see if any holes match a better pin-out to see if rewiring can be minimized. ... Quote Link to comment Share on other sites More sharing options...
Osgeld Posted October 15, 2016 Share Posted October 15, 2016 how does the picture look Quote Link to comment Share on other sites More sharing options...
icemanxp300 Posted October 16, 2016 Author Share Posted October 16, 2016 It looks good. It is dark enough w/out the 75ohm resistor. I will leave it out. Not interested in seeing it any darker. Quote Link to comment Share on other sites More sharing options...
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