Top loader AV mod and tech questions

[The Manimal]

I was going to post this in the other thread but that is for input on the new pins, and this is something different. I still want/need to fix my toaster NES's.... but..

I might go ahead and try modding my top loader for AV and see how that works out. I do not like the lines or the bad RF video, but perhaps it won't look as bad if it's cleaned up... That thing works just about every time minus some carts I have which still require several inserts because they even though they are clean of dirt and dust, they have grime on the connectors that need to be scrubbed big-time.

Omnedon....I noticed with my top loader that the port for the AC adaptor looks pretty rough. I did buy this used a good 7 years ago, but I noticed that the piece of metal that is in there (not the pin but some kind of metal flap in there) looks pretty bad....Not sure if that was supposed to be silver but it looks all corroded. It works, still. Also, I remember the RF connection requiring some twisting of the cable end to work sometimes...I think it's a similar problem. I am guessing these need to be polished with some kind of metal cleaner? I have never taken the thing apart and I'm not sure if those parts are even accessible (especially the part for the AC adaptor). But like said, I saved some instructions for this AV mod but the instructions and pictures arent' very descriptive. They show one end of the wire and don't show the other end. Likewise, they say to cut the trace underneath....they are speaking of the connection on the board itself that I need to 'burn' off completely? If so, I know I will have to be careful with that because I don't want to rip off more than I should.. Perhaps this is really simple and I'll notice that when I actually start it. Five wires is nothing...

http://www.gamesx.com/rgbadd/nes2avmod.htm

[omnedon]

I've never done that mod.

This needs it's own thread, with more than my voice added to it.

[The Manimal]

Ok.


Other question that anyone may know that I don't....


The stereo headphone plug pictured is for the both audio and video or video only?. Would I need two jacks for both audio and video? For the audio, would I need something to amplify the signal also, or would I just go directly to the output on the back from the point that is shown in the pictures as 'audio out'? I really wish there was a photo of how they attached the jacks in the back because I really do not want to screw this thing up. It should not be difficult, as I've done those little circuit radio kits that they sell at Radio Shack before...it was years ago, and I'd probably buy another just to get the hang of it again...


Another question....about the 'amp'. I'm assuming the amp is the transistor, and each of the three legs are what I attach wires to.. I looked up the part and the legs are excessively LONG. Where am I supposed to mount this thing? Do I trim off the ends so that they are shorter? Where do I put the resistors?...do I need also to buy one of those little boards and do all the connections on that thing, and then tape it to the inside of the casing?

There's this schematics for the mod:

http://www.gamesx.com/grafx/nes_schm.gif

Those connections between resistors, do I need additional wiring or what? Grrr...

[davidleeroth]

I've done that to a Famiclone.
There isn't many parts so you can just solder it all together and wrap it up with tape so there won't be shorts. You can use breadboard and trim the legs too if that suits you better.

Headphone jacks have audio for left and right and ground and since NES is mono the other audio is used to carry video signal. No amp is needed for audio (at least in my Famiclone).

[The Manimal]

In the diagram, after the 220 and 1.3K ohm resistors, are those both ground? (Honestly, I don't know what those "ends" are supposed to be.) The instructions and picture only show one ground wire, so if this is the case, I'm confused. I don't connect those two wires together and join them to a single ground wire (which goes to the corner of the board, as shown in the picture), do I? What about audio when it comes to ground? You mention ground, but it appears from this page that I just solder a wire from the point shown on the NES's board directly to the output?


Also, as far as removing the trace that is on the NES's board itself at R3....how to do that? I remember in shop class (barely! This was a H.S. class 9 years ago) that if you put your soldering iron onto the board itself, the tracing would stick to it and you'd rip a bunch of it off the board, or ruin the board by burning it.... I need the best way to approach this.


The instructions don't mention any additional wires or breadboard, so I'm guessing now for the first time (after re-reading yours now) that they did this. Soldered each resistor directly to another resistor, etc. But if I were to use a board, I would need additional wires unless some tracing is already on the board itself (correct?).

[The Manimal]

BTW, I am thinking I may want to put TWO holes in the back corner instead and do actual RCA jacks... Hopefully there is that much room to work with. Not sure on this. Would I connect just one wire to the RCA connector (video or audio) or would there be another (ground once again)?

use a hand drill or electric drill? i have both but i'm not sure how strong the plastic shell is (i don't want it to crack on me). with the rca jacks on the case, i'd need to superglue them on the inside to the case so they are 'stuck' and don't jiggle around? I don't want to push the cable on and have the RCA jack move inward and fall inside the NES...

also if you happen to know, a good size diameter for the hole.


Thank you in advance...

I feel really annoying and dumb asking all of this.

[davidleeroth]

In the diagram, after the 220 and 1.3K ohm resistors, are those both ground? (Honestly, I don't know what those "ends" are supposed to be.) The instructions and picture only show one ground wire, so if this is the case, I'm confused. I don't connect those two wires together and join them to a single ground wire (which goes to the corner of the board, as shown in the picture), do I? What about audio when it comes to ground? You mention ground, but it appears from this page that I just solder a wire from the point shown on the NES's board directly to the output?

Yeas, they are ground and yes, you connect them all together and join to a single ground wire.

Also, as far as removing the trace that is on the NES's board itself at R3....how to do that? I remember in shop class (barely! This was a H.S. class 9 years ago) that if you put your soldering iron onto the board itself, the tracing would stick to it and you'd rip a bunch of it off the board, or ruin the board by burning it.... I need the best way to approach this.

Exacto-knife is good.

The instructions don't mention any additional wires or breadboard, so I'm guessing now for the first time (after re-reading yours now) that they did this. Soldered each resistor directly to another resistor, etc. But if I were to use a board, I would need additional wires unless some tracing is already on the board itself (correct?).

Yeah, or you can just bend the resistor ends so they touch each other and solder them together. The main thing is to make a connection.

Electric drill is good, just go slow. There are special RCA jacks for case mounting (I think the proper term is CTFA or GRFA, google for pics) which have the ground point sticking from the side. They're won't jiggle or wiggle.

[The Manimal]

Electric drill is good, just go slow. There are special RCA jacks for case mounting (I think the proper term is CTFA or GRFA, google for pics) which have the ground point sticking from the side. They're won't jiggle or wiggle.

I am all ready to go except for this part...

if you have the ground going to the corner of the main board like in the picture, I wouldn't need to put grounds on the RCA jacks themselves? But I could if I wanted, ground those various wires on the RCA jacks and not on the main board. (meaning one or the other)

I am thinking now that that the audio isn't shown to have a ground added because 1) the audio signal doesn't need to be amped for both outputs and 2) it is already grounded as part of the RF...

I might have a question about the RF connection after I open it up (I will have to order a security bit beforehand). I don't have to make any changes to that, do I? Remove any wires, add any to it, etc...

[davidleeroth]

You should ground both RCA jacks to the mainboard, every signal has to have a ground. If for no other reason but to help reduce interference. Using the headphone plug, the video and audio share the ground inside the connector so there's only three wires connected to the plug.

No mods necessary for the RF unit.

[The Manimal]

You should ground both RCA jacks to the mainboard, every signal has to have a ground. If for no other reason but to help reduce interference. Using the headphone plug, the video and audio share the ground inside the connector so there's only three wires connected to the plug.

No mods necessary for the RF unit.

Why do you have to run a third wire to the headphone plug, if it's already grounded on the main board already? Not really understanding this.. Unless this is for the audio, and that point pictured in image #2, center, should have TWO wires coming from it?

I typed out something about the RF but I realized what I was saying didn't make sense and I removed it

[davidleeroth]

I don't really know how to break it down.
Audio out is not ground, in this project it's the point where you take the audio signal and connect it to the RCA plug.

If the headphone plug is grounded already there's no need for another ground but screwing it on the plastic case and connecting video and audio ain't gonna ground the plug.

Anyways, I think you would be most pleased to learn some basic stuff first. There are some good books in the library and various online sources of course. At least in my case, pretty much every electronics project where I didn't know exactly what I was doing ended up on my scrap pile. And if it didn't, troubleshooting electronics isn't fun.
Maybe you could pay someone to do it (shouldn't be too expensive) and then open it up and learn from that?