NES 2 TOP LOADER A/V MOD

[raylyd]

hi i have done http://www.gamesx.com/rgbadd/nes2avmod.htm
but i get colours runing any help for a fix would be greatfull
i am happy i got output from this console is its a us console but the rf lead would not work on a pal tv for some reson

[Calpis]

Are you using that exact transistor? I suggest trying another circuit where you can use any general purpose transistor. As I understand it, the PPU already outputs TV level so the idea is not to amplify it, but to just buffer it with a "common collector"/"emitter follower" amplifier. Here are some circuits I've collected:



I'd go with the AV FC circuit. (Note that the 75 ohm resistor is your TV.)

[DarthCloud]

Like Calpis said use the AV famicom circuit instead, this will give you the best composite video signal here the exact circuit:



You can borrow some part from the current video amp (like the transistor IIRC) of the top loader NES just remove them and build you new amp circuit with that.

[raylyd]

ok i will try soon as
guess what found 2sa937 on ebay
as toster model is hard to come buy where i live

[DarthCloud]

ok i will try soon as
guess what found 2sa937 on ebay
as toster model is hard to come buy where i live

Like I said their is already one in your NES just use this one, since it's used in the video circuit it's ok cause you are building a new video circuit. Unless you still want to use RF for some weird reason.

[raylyd]

if theres no need to build a new video circuit just mod what i have so i can use bit from nes with out damage let me know as i dont want to damge the unit thanks mate the rf is uless as i am in the uk and its a usa console thanks mate take care

[raylyd]

hi mate got around to try it i could not get it to work anyone got picturs of one allready done thanks
or if not i am willing to pay someone to do the mod for me as its been doing my heading cheers and merry christmas to all that read this

[raylyd]

i am willing to pay someone for this mod please help me

[bacteria]

Did you ever get this resolved?

The NES toaster model has built in composite. Looks fine, i'm modding one at the moment, video quality is fine.

[raylyd]

no so i sold it for about £90 on ebay

[raylyd]

i got a toster nes now i got it from a boot sale i have not had the chance to even test it yet could i do s/video on this nes uk pal model how easy is it to disable region lock out thanks

[bacteria]

Region free is mega easy - snip off pin 4 of the 319 chip, there are many YouTube videos on that simple process. This apparently makes 95% of all NTSC games run, although 75% run perfectly, on the other 25% you can get text garbled. Tested on the couple of NTSC NES games I have and they work fine, although of course running at PAL speed not NTSC speed.

S-video - i'd be interested in that, was going to investigate that myself as the composite output is ok but not perfect. The resistor off the transistor that feeds to the composite line seems to be 69 ohms (according to my multimeter), was going to see if used a standard 75 ohm one if that made any odds or not too.

[raylyd]

ok cool thanks mate

[bacteria]

S-video - discussed on this thread: http://www.sega-16.com/forum/showthread.php?p=204955

It says basically that you'll not improve the video quality as the composite signal is native. You can RGB mod with butchering another system, however the improvements on the pics i've seen are minimal and the parts needed aren't easy to get.

[raylyd]

i will just leave the s/video out just put extra audio out put one extra only about £2 to get the phono connecter take care buddy

[undamned]

Thanks for the schematics, Calpis and DarthCloud! Those helped me to do an AV mod for a friend recently! :-)
Build log here: http://therealundamned.blogspot.com/...d-led-mod.html
-ud

[Cauterize]

I finally got round to modding a Top Loader NES with one of the guides i found online, however I have hit some troubles with it. In case it helps, I have a US Top Loader and I am based in the UK (PAL TVs etc)

Using the following guide, the AV out gives me the following picture quality:
Guide - http://nesdev.parodius.com/bbs/viewt...=asc&start=105 (Few posts down)







Not only are all the colours really dark (doesn't show too well in the pictures unless you look at the clouds), but the mod seems to really struggle with the colour black. When you go onto the screen which tells you how many lives Mario has, the TV loses signal and shows a black screen and the AV channel number I'm currently on.

To add to that, as the first picture and third picture shows, any areas with a lot of black that doesn't result in a blank screen seems to distort horizontally.

To my knowledge I have followed the guide perfectly, however the results (as shown) suggest otherwise. I'm hoping someone can quickly point out the error, as it's beyond me :(

[ApolloBoy]

Can you post a picture of the mod itself? I've done several of these without fuss and I think I can figure out what went wrong with yours.

[gorgyrip]

Do you have the same problems when using rf? Have you tested it on another tv?

[MottZilla]

It could be the signal is too weak. Did you use a resistor in this mod of the proper value? Or maybe you need a capacitor in there somewhere or use the wrong value of that?