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PostPosted: Sun Aug 02, 2015 1:27 pm 
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Hi guys,

First of all i would like to say i should have been on this forum way earlier but i guess i didnt realized the NES was so unique and well conceived for it's time. Nintendo truly did make miracles with this 8 Bit system.

Anywais with that said.. I'm currently in the process of refurbishing and re-capping NTSC front-loader NESes but in my testing i realized i had at least two different models and maybe even more different board revisions.

I did some testing with one unit which has an Alps RF modulator/power supply bloc and after hooking it up true componant on my LED TV i noticed evenly spaced "jailbars" from the pale colors. Mostly visible with pale blues sky some light brown and light green palettes.

I would take screen shots or/and captures of Super Mario Bros. to show what i mean if necessary but i want to know how this is possible on unmodded NES consoles. Video signal is too weak for all i know... I read alot about this issue but it seemed to be only present on some PAL top-loaders and mostly only appeared after RGB mods. I may be wrong buty i don't think i've come across lots of topics with unmodded Front-loader NES having jailbar problems.

I would also like to mention that i didnt see this issue on front-loader NES wich had a Mitsumi RF/power supply bloc but after hooking that same system two differents capture card (hauppauge PCI HVR-1600, and some Pinnacle 7$ clone i got from ebay; i have direct componant input on both of these cards) i get jailbars even worst on the clone that i cant get on my HDTV but on the hauppauge i seem to get a decent video output but with some faint diagonals lines :/.

All that said i need to do some more testing to sort all this out; i have taken the rf/power bloc and connect pin 21 from PPU to an small basic video amp circuit to see if i still get jailbars so on and so. I already mounted the PPU for the console i'm testing with on a 40 pin DIP socket and changed all electrolitics capacitors on the board with no really noticable differences with those jailbars.

In the end i will need find a solution to bring these consoles as new as possible with strong video out signal (without jailbars at all) but without adding componants or modifying the console other than maybe remove some unecessary componants to simplifying the video signal circuit. Those maybe will come later with as reburbished mod ready consoles or something on ebay (still don't know i got like 20 of them nad might get alot more in the future lol).

I'm still in the process of completing a little 5 volt test station to easily test the repair or modifications without soldering de-soldering 100 times the rf/power bloc but if i can get any pointers in this forum i will take any advices i can from experienced techs i will gladly take them.

Edit: All references to Componant video is of course wrong. I meant composite.


Last edited by danyboy666 on Sun Aug 02, 2015 2:00 pm, edited 2 times in total.

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PostPosted: Sun Aug 02, 2015 1:30 pm 
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First things first: I'm assuming you are referring to composite video, not component video, which is different in the way color data is encoded. The NES systems all output Composite Video - the one with the yellow jack.

As for the jailbars, many systems seem to just get them. The NES front-loaders are a lot better about it than the top-loaders, and there is some variance from one system to another.

Causes for the jailbars are usually a mix of interference from nearby circuitry, and fluctuations in power draw (think the SNES DRAM refresh bars). The former is influenced strongly by board layout, which is why the frontloader seems to have much reduced jailbars.


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PostPosted: Sun Aug 02, 2015 1:36 pm 
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mikejmoffitt wrote:
First things first: I'm assuming you are referring to composite video, not component video, which is different in the way color data is encoded. The NES systems all output Composite Video - the one with the yellow jack.

As for the jailbars, many systems seem to just get them. The NES front-loaders are a lot better about it than the top-loaders, and there is some variance from one system to another.

Causes for the jailbars are usually a mix of interference from nearby circuitry, and fluctuations in power draw (think the SNES DRAM refresh bars). The former is influenced strongly by board layout, which is why the frontloader seems to have much reduced jailbars.



Yes. Analogue composite my bad :/ my brain is fried.

I will be getting into lots of testing really soon. Thanks for this pointer.

p.s.: Oh well after some reach on this forum, user leonk experienced the same troubles i've come across with the front-loader http://forums.nesdev.com/viewtopic.php?f=9&t=601&start=165
It seem all i would need is to clean the power line of any interferences. I'll check wheter it would improve the video signal with some strategicaly placed decoupling caps. Anywais it seem i need to do some reading.


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PostPosted: Mon Aug 03, 2015 1:25 pm 
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thanks for your help you all

Should've known I wouldn't get any help from these forums lol thanks anywais guys i'll manage.


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PostPosted: Tue Aug 04, 2015 12:38 pm 
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danyboy666 wrote:
thanks for your help you all

Should've known I wouldn't get any help from these forums lol thanks anywais guys i'll manage.

You gave people only a day, and I tried to give you some information. A lot of people here are busy.


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PostPosted: Tue Aug 04, 2015 2:28 pm 
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mikejmoffitt wrote:
danyboy666 wrote:
thanks for your help you all

Should've known I wouldn't get any help from these forums lol thanks anywais guys i'll manage.

You gave people only a day, and I tried to give you some information. A lot of people here are busy.


Well from what i know after all my research on the web people are way into more RGB mod stuff and upscaling to HDMI than actually try to improve the actual console without ripping the hell out of it. I,ve seen so many horrible mod jobs i coudn't even conceived some "professionals" were so bad. Actually killing old arcade boards to improve a console wich was never meant to do more than composite is beyond me lol.

The console was fine the way it was. upgrading image resolution should come way after improving the existing signal. We need to find ways for the users to actually plug these old console on modern TVs without having them purchase 200-300$ modding kits and half way destroy their boards in the process.

As for my reaction after one day it's due to the fact the after being viewed by over 60 people i didndt get any response that i couldn't get with after couple minutes google search. I understand people are busy but still...

Not that i didnt appreciate your reply. You were really fast to point me in the right direction and i thanked you for that. But maybe i expected a little more from a specialized hobbyist site like this.

edit: I get that my componant mix up didnt help me get a good first impression tough lol.

Like i said before i'll provide every info i can to help others brainstorm this issue. I wouldnt be on this forum asking for help if i knew this was common problem. For all i know i taught the only console that had this problem were consoles modded with RGB and some unmodded top-loader revisions that came out in europe. The info about unmodded NTSC NES with jailbars is not common at all from what i've gattered on google. Since i have a stack of them i will surely start a database with all infos i am able to gather with the consoles i have on hand.

Like you said. NES toasters are suppose to be reputed for being the BEST NESes out there but clearly with the test i've done here they are far from perfect.


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PostPosted: Tue Aug 04, 2015 3:11 pm 
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danyboy666 wrote:

Well from what i know after all my research on the web. People are way into more RGB mod stuff and upscaling to HDMI than actually try to improve the actual console without ripping the hell out of it. I,ve so many horrible mod jobs i coudn't even conceived some "professionals" were so bad. Actually killing old arcade boards to improve a console wich was never meant to do more than composite is beyond me lol.



People generally do not steal 2C03 RGB PPUs from arcade machines anymore. The NESRGB + the XRGB Mini Framemeister is the current way to go to hooking up the NES to modern TVs. My 4K TV won't even display any kind of 240p signal, RF, composite or component. My older 1080p HDTV does, but the NES's native composite video looks like crap and is laggy due to the upscaling. Very soon there will be the HiDefNES mod available that gives native HDMI output to NES graphics and recreates NES audio.


Quote:
Like i said before i'll provide every info i can to help others brainstorm this issue. I wouldnt be on this forum asking for help if i knew this was common problem. For all i know i taught the only console that had this problem were consoles modded with RGB and some unmodded top-loader revisions that came out in europe. The info about unmodded NTSC NES with jailbars is not common at all from what i've gattered on google. Since i have a stack of them i will surely start a database with all infos i am able to gather with the consoles i have on hand.

Like you said. NES toasters are suppose to be reputed for being the BEST NESes out there but clearly with the test i've done here they are far from perfect.


The best Nintendo 8-bit consoles for noiseless composite video are the Famicom AV and its close cousins : the rare Australian PAL Top Loader with RF output, the even rarer US Top Loader with a revised PCB and RF or Multi-Out AV output.

I would suggest finding the Australian PAL Top Loader and switching the PAL chips and crystal for the NTSC chips (rev-H) and crystal. Then remove the RF output and do an AV mod.

Believe me I am wholly sympathetic with trying to get the best quality, most-jailbar free composite video output from a Nintendo 8-bit console.

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PostPosted: Tue Aug 04, 2015 3:29 pm 
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Great Hierophant wrote:
danyboy666 wrote:

Well from what i know after all my research on the web. People are way into more RGB mod stuff and upscaling to HDMI than actually try to improve the actual console without ripping the hell out of it. I,ve so many horrible mod jobs i coudn't even conceived some "professionals" were so bad. Actually killing old arcade boards to improve a console wich was never meant to do more than composite is beyond me lol.



People generally do not steal 2C03 RGB PPUs from arcade machines anymore. The NESRGB + the XRGB Mini Framemeister is the current way to go to hooking up the NES to modern TVs. My 4K TV won't even display any kind of 240p signal, RF, composite or component. My older 1080p HDTV does, but the NES's native composite video looks like crap and is laggy due to the upscaling. Very soon there will be the HiDefNES mod available that gives native HDMI output to NES graphics and recreates NES audio.


Quote:
Like i said before i'll provide every info i can to help others brainstorm this issue. I wouldnt be on this forum asking for help if i knew this was common problem. For all i know i taught the only console that had this problem were consoles modded with RGB and some unmodded top-loader revisions that came out in europe. The info about unmodded NTSC NES with jailbars is not common at all from what i've gattered on google. Since i have a stack of them i will surely start a database with all infos i am able to gather with the consoles i have on hand.

Like you said. NES toasters are suppose to be reputed for being the BEST NESes out there but clearly with the test i've done here they are far from perfect.


The best Nintendo 8-bit consoles for noiseless composite video are the Famicom AV and its close cousins : the rare Australian PAL Top Loader with RF output, the even rarer US Top Loader with a revised PCB and RF or Multi-Out AV output.

I would suggest finding the Australian PAL Top Loader and switching the PAL chips and crystal for the NTSC chips (rev-H) and crystal. Then remove the RF output and do an AV mod.

Believe me I am wholly sympathetic with trying to get the best quality, most-jailbar free composite video output from a Nintendo 8-bit console.


I see. I understand some higher resolution TV werent really meant to display espaclly LED TVs low res but still they should at least let the analog signal passtrue. I guess there will be limits So improving the actual system video output is almost impossible without completely switching PCB's to those newer revisions. Would isolating the signal output from the PPU and running it true a shielded wire in the existing RF box would reasonably reduce the noise it gets from the bad PCB? I,ve seen some people mention it but noone seem to agree to what is the cause of this noise in the first place.... Some say bad power supply other say interference from the bad PCB design itself... Kind of hard to figure when everyone disagree. I don't have a lot of equipment on hand but still usually manage to do alot with good info.


Last edited by danyboy666 on Tue Aug 04, 2015 4:22 pm, edited 1 time in total.

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PostPosted: Tue Aug 04, 2015 3:56 pm 
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danyboy666 wrote:
Great Hierophant wrote:
danyboy666 wrote:

Well from what i know after all my research on the web. People are way into more RGB mod stuff and upscaling to HDMI than actually try to improve the actual console without ripping the hell out of it. I,ve so many horrible mod jobs i coudn't even conceived some "professionals" were so bad. Actually killing old arcade boards to improve a console wich was never meant to do more than composite is beyond me lol.



People generally do not steal 2C03 RGB PPUs from arcade machines anymore. The NESRGB + the XRGB Mini Framemeister is the current way to go to hooking up the NES to modern TVs. My 4K TV won't even display any kind of 240p signal, RF, composite or component. My older 1080p HDTV does, but the NES's native composite video looks like crap and is laggy due to the upscaling. Very soon there will be the HiDefNES mod available that gives native HDMI output to NES graphics and recreates NES audio.


Quote:
Like i said before i'll provide every info i can to help others brainstorm this issue. I wouldnt be on this forum asking for help if i knew this was common problem. For all i know i taught the only console that had this problem were consoles modded with RGB and some unmodded top-loader revisions that came out in europe. The info about unmodded NTSC NES with jailbars is not common at all from what i've gattered on google. Since i have a stack of them i will surely start a database with all infos i am able to gather with the consoles i have on hand.

Like you said. NES toasters are suppose to be reputed for being the BEST NESes out there but clearly with the test i've done here they are far from perfect.


The best Nintendo 8-bit consoles for noiseless composite video are the Famicom AV and its close cousins : the rare Australian PAL Top Loader with RF output, the even rarer US Top Loader with a revised PCB and RF or Multi-Out AV output.

I would suggest finding the Australian PAL Top Loader and switching the PAL chips and crystal for the NTSC chips (rev-H) and crystal. Then remove the RF output and do an AV mod.

Believe me I am wholly sympathetic with trying to get the best quality, most-jailbar free composite video output from a Nintendo 8-bit console.


I see. So improving the actual system video output is almost impossible without completely switching PCB's to those newer revisions. Would isolating the signal output from the PPU and running it true a shielded wire in the existing RF box would reasonably reduce the noise it gets from the bad PCB? I,ve seen some people mention it but noone seem to agree to what is the cause of this noise in the first place.... Some say bad power supply other say interference from the bad PCB design itself... Kind of hard to figure when everyone disagree. I don't have a lot of equipment on hand but still usually manage to do alot with good info.

edit: yeah removing the RF part is probably the way i'll go for the ALPS RF blocs i have on hand if i can't get any impovement at all. I was looking at a way to use that circuit and use it to output to s-video instead. s-video isnt that hard to figure out an it would be next to impossible to distinguish that the console had been modded at all aprt from the different connector. But that a long way off in my head right now. If at the end i need two console to make one good at the end it's not whort the effort at all since i'm really not into destroying electronics or even rendering it unusable.


You should strongly consider the NESRGB then, it does not require sacrificing anything. You desolder the PPU, install a socket, plug in the NESRGB, put the desoldered PPU in the provided socket, then pick whatever outputs you please. You can get RGB, RGB-derived S-Video (far superior to composite-derived S-Video), RGB-derived composite video and native composite video straight from the PPU. You can get component video by soldering a small adapter from the NESRGB maker.

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PostPosted: Tue Aug 04, 2015 4:32 pm 
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Recreating CPU/PPU functions is an emulated solution not a fix. From what i learned this is not 100% compatible with the nintendo library. But at the end I see what you mean though but it still an expansive fix for seemingly easy problem.


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PostPosted: Tue Aug 04, 2015 5:57 pm 
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danyboy666 wrote:
Recreating CPU/PPU functions is an emulated solution not a fix. From what i learned this is not 100% compatible with the nintendo library. But at the end I see what you mean though but it still an expansive fix for seemingly easy problem.


There is no emulation involved, it simply assigns RGB color values to the NES's palette entries in place of NTSC or PAL encoded colors. That is what the Nintendo 2C03 RGB PPU does, the NESRGB board does a much better and more compatible job. There are no real issues with NES games anymore with the NESRGB, if there ever were. In fact, you may be able to get rid of the jailbars by using the NESRGB's AV amplifier in place of the NES's built-in amplifier.

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PostPosted: Tue Aug 04, 2015 6:09 pm 
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Great Hierophant wrote:
danyboy666 wrote:
Recreating CPU/PPU functions is an emulated solution not a fix. From what i learned this is not 100% compatible with the nintendo library. But at the end I see what you mean though but it still an expansive fix for seemingly easy problem.


There is no emulation involved, it simply assigns RGB color values to the NES's palette entries in place of NTSC or PAL encoded colors. That is what the Nintendo 2C03 RGB PPU does, the NESRGB board does a much better and more compatible job. There are no real issues with NES games anymore with the NESRGB, if there ever were. In fact, you may be able to get rid of the jailbars by using the NESRGB's AV amplifier in place of the NES's built-in amplifier.



I hear ya. But you're not gonna sell me a RGB mod kit ;)

Joking apart I'll come up with my own solution if it really comes to that. I have some ideas to get better signal without major hardware modifications. Just tought somebody else had already taken the same route i am in right now. As you said earlier there will always be issue from one TV/video outputing devices to another. In a way playing these console with their signal in the state it is now should be used on CRT monitor. At the end the choice will always comes from the users preference and tolerance level i guess.


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PostPosted: Tue Aug 04, 2015 6:56 pm 
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Great Hierophant wrote:
There is no emulation involved, it simply assigns RGB color values to the NES's palette entries in place of NTSC or PAL encoded colors. That is what the Nintendo 2C03 RGB PPU does, the NESRGB board does a much better and more compatible job. There are no real issues with NES games anymore with the NESRGB, if there ever were. In fact, you may be able to get rid of the jailbars by using the NESRGB's AV amplifier in place of the NES's built-in amplifier.

There's a slight amount of "emulation" involved, since NESRGB needs to keep track of PPUADDR/DATA writes to keep track of the state of the palette and to override the real PPU's palette. If somebody was really committed, they could probably come up with a ROM that exploits the differences between the NESRGB implementation and the real PPU to make something that doesn't work properly on NESRGB. But it's not really a problem as a far as commercial games (and homebrew games) are concerned, because they tend to use the hardware as was intended.

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PostPosted: Tue Aug 04, 2015 8:33 pm 
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I ran the NESRGB output's composite to the NES's old composite jack and it looked as good as composite ever has.

If you are looking for an improved NES image, the NESRGB or High-Def NES Kit are the real solutions for you. With composite, you can only polish a turd so much.


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PostPosted: Tue Aug 04, 2015 9:18 pm 
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mikejmoffitt wrote:
I ran the NESRGB output's composite to the NES's old composite jack and it looked as good as composite ever has.

If you are looking for an improved NES image, the NESRGB or High-Def NES Kit are the real solutions for you. With composite, you can only polish a turd so much.


Like i've said. The problem isnt present on every console. Plus it seem to vary from tv to tv. The units i've tested with ALPS RF modulator from what i see gives me instant jailbars on my TV but Mitsumi RF even though the jailbars don't seem to show up on my TV, they do show up bright as day true my capture devices. Those same capture devices i use to convert stuff from VHS and other any other stuff i capture true composite and gives me great results everytime.

I still might have lots of more testing to do but i'm pretty conviced the problem will be there no matter what i do unless i find a way to give a clean signal to the NES output or do your way and convert to RGB and have that board give it a clean video output.

Still think there should be a DIY way to fix that would take care of what it seem a common problem without completely screw up those boards because of poor skills. Even if lots of them are handled professionnaly now it is still a major modification to do to a board to get cleaner signal.

Anywais i'll keep at it and try to find so basic fix and post results here for future reference. The only reason is like i've said earlier in this thread, people can't agree on what is the problem. So no definitive fix is ever proposed at the end and threads gets piled up with RGB stuff.

edit: just found someone who said he has serviced over a 100 front-loader NESes and he noticed jailbars on almost all them. Those who didnt have them were the latest board revisions. (pretty sure they are the ones who cames out with Mitsumi RF).


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