work in progress.

today i got my multimeter out and tested all of the pins on the ppu for continuity and also tested the sync wires. everything was good. i also built the 5v scart switching circuit to switch things to 4:3 and Rgb on.

NONE of this changed anything at all.

ive read everything i can find about this setup still nothing clicks it seems like ive tried everything. i definately have continuity on the sync wire and the Rgb.

its like the signal is nonexistant. mabeye i lucked out and got a ppu that has some kind of issue inside. i wouldnt know how to tell though.

"i wouldnt know how to tell though."

what i meant to say was, i cant afford another ppu. Id love to just have one sitting here to swap in.

one detail i dont think i mentioned. i tapped sync off of pin 21 direct from the ppu. But should i have lifted it or does it need to stay connected to the pcb for some reason? im trying to eliminate everything else i can think of.

mvsfan wrote:

one detail i dont think i mentioned. i tapped sync off of pin 21 direct from the ppu. But should i have lifted it or does it need to stay connected to the pcb for some reason? im trying to eliminate everything else i can think of.

I always keep ppu pin 21 disconnected from the pcb when I tap it

im going to hook this up to an arcade monitor as soon as i move the junk in front of the cabinets.

simple idea. this thing should light up like any other jamma board would without the extra junk. that way i can eliminate any issues with the tv, encoder, or scart.

now ill have to study the playchoice to see what components the video lines off of the ppu are going through before they hit the jamma connector.

mvsfan wrote:

im going to hook this up to an arcade monitor as soon as i move the junk in front of the cabinets.

simple idea. this thing should light up like any other jamma board would without the extra junk. that way i can eliminate any issues with the tv, encoder, or scart.

now ill have to study the playchoice to see what components the video lines off of the ppu are going through before they hit the jamma connector.

Just a simple 1 or 2 transistor video amp. I don't think I checked what sync goes through.

i decided to stop posting about this a while ago until i made any progress at all.

i discovered the problem by accident.

I tried to test some jamma boards through a converter before i sold them on ebay, and i also could not get sync out of them, when hooked up to my sony wega tv.

I then hooked up my rgb nes to the same arcade rgb>svideo converter and hooked it up to a 20 year old sylvania tv i had in the garage,

and it WORKS FINE. the rgb nes works.

so now im trying to figure out what i need to add for the nes to light up through component on the sony. damn thing works with everything else i throw at it but not this nes.

Are you using a rgb to component video converter?

Drakon wrote:

Are you using a rgb to component video converter?

for my jamma boards i normally use a supergun with an rgb>svideo converter. i just went to test some recently and they dont work on my sony wega.

so then i plugged them into the old sylvania through s-video and they worked fine as always.

so then i got the idea to wire the rgb nes up to the s-video converter in the supergun. on the wega it wont sync. on the old sylvania it works great.

so then i took my rgb>component converter and hooked up the supergun through it to the wega. wont sync, and same with the rgb nes. PROBLEM solved, sort of.

what i dont get, is that my saturn, dreamcast, snes, and x-eye all work fine (and look awesome) through the same component converter, on the wega crt but the rgb nes, and jamma boards dont.

I was looking at the nes all this time. Sometimes the best way to solve a frustrating problem is to simply walk away from it for a while.

the jamma and the nes must need some extra part that the systems that do work have.

You might just need to add a resistor on the luma line. My component video tv likes my rgb to component circuits but to get the signal working on my component video capture device I needed to add a resistor on luma for it to sync properly.

what value should i try first?

i think i just found the answer on arcadeshop.com. in some info about the jrok converter i found this.

"Are there any known problems. ?

The only known problems are with later Midway games such as Smash TV, NBA JAM, Mortal Komat ( 1, 2 & 3 ) . These games use a vertical sync. frequency of around 56Hz ( the majority of games having a vertical sync of around 60Hz ). This vertical sync. frequency appears to be incompatible with some Sony TV sets, most notably the Sony WEGA series. These sets cannot sync to this frequency and the picture will roll vertically.

This is NOT a problem with the output from the converter is it purely a problem with the TV receiver."


Perhaps the nes uses the same frequency, i dont know.

Yikes that sucks. I didn't know certain stuff isn't 60 hz

i knew some stuff wasnt 60hz, mostly pc monitors.

but i had no idea the nes was one of these.

anyway, ive read that its possible to adjust the sync frequency on the wega down by 5% in the service menu. i have the service manual and know how to get into the menu but no idea what setting to adjust, or if it will make other stuff (the stuff that works now) not sync anymore.

i wish i knew more about this.

well, im gonna look at the good side here, at least i figured out that its not my nes that i worked so hard on!

Haha yeah that's always good to know

im going to add a potentiometer to the sync line on my nes and see if i cant just dial it in to sync.

i stuck a resistor on it
and i noticed that the picture was trying to come on, i got color intermittently. so instead of fooling around with swapping resistors, i just want a pot i can turn hopefully that will do it.

any idea what range of potentiometer i should use? i honestly have no clue what the resistor is doing but it appears to clear things up a bit.

mvsfan wrote:

im going to add a potentiometer to the sync line on my nes and see if i cant just dial it in to sync.

i stuck a resistor on it
and i noticed that the picture was trying to come on, i got color intermittently. so instead of fooling around with swapping resistors, i just want a pot i can turn hopefully that will do it.

any idea what range of potentiometer i should use? i honestly have no clue what the resistor is doing but it appears to clear things up a bit.

I have no clue what range to use.

Drakon wrote:

mvsfan wrote:

im going to add a potentiometer to the sync line on my nes and see if i cant just dial it in to sync.

i stuck a resistor on it
and i noticed that the picture was trying to come on, i got color intermittently. so instead of fooling around with swapping resistors, i just want a pot i can turn hopefully that will do it.

any idea what range of potentiometer i should use? i honestly have no clue what the resistor is doing but it appears to clear things up a bit.

I have no clue what range to use.

i just used a 0-1000 ohm pot. it did nothing. back to the box o' ideas.

mvsfan wrote:

Drakon wrote:

mvsfan wrote:

im going to add a potentiometer to the sync line on my nes and see if i cant just dial it in to sync.

i stuck a resistor on it
and i noticed that the picture was trying to come on, i got color intermittently. so instead of fooling around with swapping resistors, i just want a pot i can turn hopefully that will do it.

any idea what range of potentiometer i should use? i honestly have no clue what the resistor is doing but it appears to clear things up a bit.

I have no clue what range to use.

i just used a 0-1000 ohm pot. it did nothing. back to the box o' ideas.

what if i tie the sync into green on the component? will it hurt it or would there be some circuitry needed?

oh, btw i just won 2 nes consoles on ebay recently for $1.30 each + shipping. i was able to get one working sofar and the other one hasnt arrived yet.

the one i got working is a nes-cpu-07. i read one of your posts where these have very little interference when rgb modded.

im thinking of moving my rgb stuff over to it, if i get interference. the one i built is a nes-cpu-11, honestly i was just looking for the cheapest nes i could find when i set out to build this, i didnt know any better.

do you have any screen comparisons of an 07 next to an 11?

Honestly it's been ages since I modded a 11 but the screen had super strong jailbars. I'm not sure if the jailbars are because of the pcb or because of how I wired the mod. I'd actually like to try rgb modding a nes-cpu-11 again to see if I get the same huge jailbars with my current methods.

Drakon wrote:

Honestly it's been ages since I modded a 11 but the screen had super strong jailbars. I'm not sure if the jailbars are because of the pcb or because of how I wired the mod. I'd actually like to try rgb modding a nes-cpu-11 again to see if I get the same huge jailbars with my current methods.

when you get the chance id like to see a nes-cpu-11 with the new kit installed.


btw, how much is that kit without the audio? im thinking about just installing one that should solve all my issues. if i ever figure out whats wrong with my toploader, ill just transfer the kit over to it.

oh, does the kit come assembled or do you have to put it together?

You need to put it together. Here's the website where they come from:

http://homepage3.nifty.com/F-LABO/ProductsList.html

mvsfan wrote:

Drakon wrote:

Honestly it's been ages since I modded a 11 but the screen had super strong jailbars. I'm not sure if the jailbars are because of the pcb or because of how I wired the mod. I'd actually like to try rgb modding a nes-cpu-11 again to see if I get the same huge jailbars with my current methods.

when you get the chance id like to see a nes-cpu-11 with the new kit installed.


btw, how much is that kit without the audio? im thinking about just installing one that should solve all my issues. if i ever figure out whats wrong with my toploader, ill just transfer the kit over to it.

oh, does the kit come assembled or do you have to put it together?

Drakon wrote:

You need to put it together. Here's the website where they come from:

http://homepage3.nifty.com/F-LABO/ProductsList.html

mvsfan wrote:

Drakon wrote:

Honestly it's been ages since I modded a 11 but the screen had super strong jailbars. I'm not sure if the jailbars are because of the pcb or because of how I wired the mod. I'd actually like to try rgb modding a nes-cpu-11 again to see if I get the same huge jailbars with my current methods.

when you get the chance id like to see a nes-cpu-11 with the new kit installed.


btw, how much is that kit without the audio? im thinking about just installing one that should solve all my issues. if i ever figure out whats wrong with my toploader, ill just transfer the kit over to it.

oh, does the kit come assembled or do you have to put it together?

i guess i would need the 6000 yen kit with no audio. thats about 74.00. not bad i thought it would be a lot more. i like that kit theres not 1 surface mount part on it. now to get the extra $ will be a while. ive already wasted at least that on my other parts besides the ppu.

btw, besides not fitting in the case, is there any other reason you had to remotely locate the kit in the toaster? i really dont care if i have to cut that raised section in the bottom of the case out, ill just make a flat plate to go back on it.