NESRGB board available now

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vol.2
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Re: NESRGB board available now

Post by vol.2 »

Lopenator wrote:The everdrive is clean. The pin connector was boiled. Cleaned with alcohol and toothbrush and I bent the pins up. It's a tight grip but definitely not a death grip. All of the pins are not perfectly even albeit close. Maybe that can be causing a bad connection. I have a brand new aftermarket connector. Maybe I should try that.
Yeah, that might help, although some of those aftermarket guys are extremely tight and it makes it hard to pull out carts. Also there could be some cold solder joints on one of your boards, especially if there was a mod done to it. You should go over anything that's been mucked with and keep an eye out for cold joints anywhere around the video chip.
viletim
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Re: NESRGB board available now

Post by viletim »

Lopenator wrote:Does anybody know why my NES will randomly change colors during play? Sometimes it will revert back to normal and sometimes it doesn't.
It looks like the NESRGB is getting out of sync with the PPU. I have another customer with this problem on an NTSC front loading NES. What console model is yours in?
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

viletim wrote:
Lopenator wrote:Does anybody know why my NES will randomly change colors during play? Sometimes it will revert back to normal and sometimes it doesn't.
It looks like the NESRGB is getting out of sync with the PPU. I have another customer with this problem on an NTSC front loading NES. What console model is yours in?
NES 001
NTSC front loader.
KPackratt2k
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Re: NESRGB board available now

Post by KPackratt2k »

Have you replaced the timing capacitor (typically labeled C8 on the motherboard, depending on the revision) with the supplied 220 nF capacitor? I suspect that some people doing this mod themselves probably missed the notes page specific to the new version which states that the capacitor must be replaced as the stock 100 nF capacitor is too low for the reset timings that the NESRGB expects, so I figured it might be worth a shot to check.
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

KPackratt2k wrote:Have you replaced the timing capacitor (typically labeled C8 on the motherboard, depending on the revision) with the supplied 220 nF capacitor? I suspect that some people doing this mod themselves probably missed the notes page specific to the new version which states that the capacitor must be replaced as the stock 100 nF capacitor is too low for the reset timings that the NESRGB expects, so I figured it might be worth a shot to check.
Yes I replaced that.

I replaced an orange ceramic cap C8 with the blue one in the kit.

I notice svideo does not work on my retrotink. I am not sure if this is related.

Here is another example of how it looks

https://imgur.com/a/FGHqkMi
viletim
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Re: NESRGB board available now

Post by viletim »

Lopenator wrote:
KPackratt2k wrote:Have you replaced the timing capacitor (typically labeled C8 on the motherboard, depending on the revision) with the supplied 220 nF capacitor? I suspect that some people doing this mod themselves probably missed the notes page specific to the new version which states that the capacitor must be replaced as the stock 100 nF capacitor is too low for the reset timings that the NESRGB expects, so I figured it might be worth a shot to check.
Yes I replaced that.

I replaced an orange ceramic cap C8 with the blue one in the kit.

I notice svideo does not work on my retrotink. I am not sure if this is related.

Here is another example of how it looks

https://imgur.com/a/FGHqkMi
You have incorrect colours and a PPU de-syncing problem (that's what's causing the colour fringes on background objects in the second picture you posted). Is it just this game or every game? Are you using an Everdrive cartridge (original one or the newer pro version)?

Bad s-video (or composite video) is consistent with with PPU de-syncing. It looks like the quality of the clock signal is no good.

If the power on reset timing is wrong then LED 7 on the NESRGB board will blink for a few seconds at power up. I have had reports that some front loader consoles need a larger cap than 220n to start correctly. The fix in that case to put in both the 100n and 220 in parallel. Though if LED 7 is off this isn't an issue.
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

viletim wrote:
Lopenator wrote:
KPackratt2k wrote:Have you replaced the timing capacitor (typically labeled C8 on the motherboard, depending on the revision) with the supplied 220 nF capacitor? I suspect that some people doing this mod themselves probably missed the notes page specific to the new version which states that the capacitor must be replaced as the stock 100 nF capacitor is too low for the reset timings that the NESRGB expects, so I figured it might be worth a shot to check.
Yes I replaced that.

I replaced an orange ceramic cap C8 with the blue one in the kit.

I notice svideo does not work on my retrotink. I am not sure if this is related.

Here is another example of how it looks

https://imgur.com/a/FGHqkMi
You have incorrect colours and a PPU de-syncing problem (that's what's causing the colour fringes on background objects in the second picture you posted). Is it just this game or every game? Are you using an Everdrive cartridge (original one or the newer pro version)?

Bad s-video (or composite video) is consistent with with PPU de-syncing. It looks like the quality of the clock signal is no good.

If the power on reset timing is wrong then LED 7 on the NESRGB board will blink for a few seconds at power up. I have had reports that some front loader consoles need a larger cap than 220n to start correctly. The fix in that case to put in both the 100n and 220 in parallel. Though if LED 7 is off this isn't an issue.
This has happened in the only 2 games I have tried. Castlevania 1 & 2. I am using newer everdrive n8 pro.

When I get home from work today I will confirm if LED 7 blinks at start up.

If LED 7 does not blink, is this an issue with the everdrive?
Sometimes it takes hours for the colors to change. Sometimes it takes 5 minutes.
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Re: NESRGB board available now

Post by viletim »

Lopenator wrote:If LED 7 does not blink, is this an issue with the everdrive?
Sometimes it takes hours for the colors to change. Sometimes it takes 5 minutes.
I'm fairly certain the problem is with the NESRGB, I'm just trying to get as much information as possible to understand the conditions under which in manifests. I've managed to get a console that does the colour changing yesterday, so I should be able to figure out exactly what's going on in the next couple of days.
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

I am 90% sure my LED is not blinking on boot up. I did not have a chance to open it yet but this morning before work I peeked my eye into the bottom and saw a solid LED. Of course when I get home I will confirm this later today. Let me know if you come to any conclusions. Until then the console is still playable and I will be using it daily.

Thank you for the support!

Edit: I can now confirm LED 7 stays solid during bootup.
Port Zero
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Re: NESRGB board available now

Post by Port Zero »

Hi Tim,

I've installed NESRGB v4 to my AV Famicom. It works correctly with crispy pixels now. I really like this. Thank you for your hard work on such great product.

I have an issue on palette switch by the controller. I close J1 and connect 4 wires of clock, latch, data and reset. But I cannot switch palette nor reset in-game.

Image
Image

Yeah, my soldering is not good, but it's tested by multimeter. Would you give me a clue for this issue?
BigSplodge
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Re: NESRGB board available now

Post by BigSplodge »

Hi, just wondering if anybody can advise what the small black SMD component horizontally adjacent to the “J5” pad on a V2 board is?

I melted it slightly terminating a cable for audio expansion in the nearby via.

There’s no issues at all, just curious what the component is and whether I should consider replacing it.

Thanks!
Leaniel
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Re: NESRGB board available now

Post by Leaniel »

Mmh I have a Problem with my Nesrgb v4 Board.
The Audio is short to hear low then it fade in seconds.

Audio channels are connect from Chip to A and B.
And from O to Multi out.
And for expansion Audio pin 2 and 9 with 1KOhm and then pin 9 to the hole over J5

All cable working and when I bride A and B with O it's goes to the multi out.
Definitiv a Problem with the nesrgb.

A short time on the beginning Audio was no Problem.


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UnbornApple
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Re: NESRGB board available now

Post by UnbornApple »

I have a NESRGB v4 and I'm installing it in a Twin Famicom. I'm trying to figure out how to preserve the expansion/FDS audio. I found a reddit post ( https://www.reddit.com/r/retrogaming/co ... _an_audio/ ) linking to a post Voultar made in in this thread 8 years ago ( viewtopic.php?f=6&t=47617&start=3420 ) where he describes what to do. The picture he posted is gone now, but the reddit post has one. My only question is the picture mentions a 47k Ohm resistor, when Voultar's post mentions 100k.
copy
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Re: NESRGB board available now

Post by copy »

BigSplodge wrote:Hi, just wondering if anybody can advise what the small black SMD component horizontally adjacent to the “J5” pad on a V2 board is?

I melted it slightly terminating a cable for audio expansion in the nearby via.

There’s no issues at all, just curious what the component is and whether I should consider replacing it.

Thanks!
According to the BH7236AF datasheet, that is a 68 uH inductor. It is part of the Y trap filter, which reduces cross-color artifacts in the composite video output.

Leaniel wrote:Mmh I have a Problem with my Nesrgb v4 Board.
The Audio is short to hear low then it fade in seconds.

Audio channels are connect from Chip to A and B.
And from O to Multi out.
And for expansion Audio pin 2 and 9 with 1KOhm and then pin 9 to the hole over J5

All cable working and when I bride A and B with O it's goes to the multi out.
Definitiv a Problem with the nesrgb.

A short time on the beginning Audio was no Problem.
I don't know if this is causing your problem, but you also need to install a resistor in line between pin 9 and the NESRGB. The commonly used value is 47 kOhms.
Leaniel
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Re: NESRGB board available now

Post by Leaniel »

copy wrote: I don't know if this is causing your problem, but you also need to install a resistor in line between pin 9 and the NESRGB. The commonly used value is 47 kOhms.
Thx but Know that but even without that mod and removing this line the problem is there too.
At zhe moment the expansion Audio mod is remove.

Low audio and goes silent in seconds.
Most time it's that short that it not apear on the display.

All capacitor and resistor below the Audio soldering points on the nesrgb are tested and ok.
No cross contacts on the soldering points and cable are working too.

I can take the cable and desoldering and bridge them together and the Audio is there on the multi out.

Even on the chinch out the Audio works.

It's clear the nesrgb itself.

But what parts of it can it be and how to test

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viletim
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Re: NESRGB board available now

Post by viletim »

Leaniel wrote:Thx but Know that but even without that mod and removing this line the problem is there too.
At zhe moment the expansion Audio mod is remove.

Low audio and goes silent in seconds.
Most time it's that short that it not apear on the display.

All capacitor and resistor below the Audio soldering points on the nesrgb are tested and ok.
No cross contacts on the soldering points and cable are working too.

I can take the cable and desoldering and bridge them together and the Audio is there on the multi out.

Even on the chinch out the Audio works.

It's clear the nesrgb itself.

But what parts of it can it be and how to test

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Here is the NESRGB audio circuit. It's the same on all hardware versions.

Image

DC voltage on the op-amp pins should be approximately,
  • 1) 1.7V
  • 2) 0V
  • 3) 1.7V
  • 4) 1.7V
  • 5) 5V
(measured with the console on but no cartridge inserted)
Leaniel
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Re: NESRGB board available now

Post by Leaniel »

viletim wrote:
Leaniel wrote:Thx but Know that but even without that mod and removing this line the problem is there too.
At zhe moment the expansion Audio mod is remove.

Low audio and goes silent in seconds.
Most time it's that short that it not apear on the display.

All capacitor and resistor below the Audio soldering points on the nesrgb are tested and ok.
No cross contacts on the soldering points and cable are working too.

I can take the cable and desoldering and bridge them together and the Audio is there on the multi out.

Even on the chinch out the Audio works.

It's clear the nesrgb itself.

But what parts of it can it be and how to test

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Here is the NESRGB audio circuit. It's the same on all hardware versions.

Image

DC voltage on the op-amp pins should be approximately,
  • 1) 1.7V
  • 2) 0V
  • 3) 1.7V
  • 4) 1.7V
  • 5) 5V
(measured with the console on but no cartridge inserted)
Thx I will measure it in the next days.
I think the Chip can be the problem or the power line but I will se it

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jkuch77
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Re: NESRGB board available now

Post by jkuch77 »

I'm fairly certain the problem is with the NESRGB, I'm just trying to get as much information as possible to understand the conditions under which in manifests. I've managed to get a console that does the colour changing yesterday, so I should be able to figure out exactly what's going on in the next couple of days.
I'm also having the color changing issue with the new NESRGB v4. I'm also using an everdrive n8 pro and frontloader NTSC NES. I did swap out the C6 cap. The issue seems to happen on screen transitions for me. For example, in Mike Tyson's Punch-Out after a match when the screen transitions to the next match or sometimes even after a round. It does go back to normal colors eventually and that also happens during the screen transitions. I also decided to replace the caps on C1, C9, and C23, which seems to have caused the color changing issue to happen less often, or maybe just coincidence. Hope this helps. Looking forward to a solution!
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

I have replaced all caps and issues still is present.
viletim
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Re: NESRGB board available now

Post by viletim »

Lopenator and jkuch77,

There's a metastability bug in the NESRGB V4, it prevents/corrupts palette updates so colours go wrong. I think it should be possible to avoid it by changing the timing of the appropriate signal a little bit.

Try this: connect a small ceramic capacitor between pin 13 of the PPU (CE#) and ground. Some value between 22p and 56p should be good. It's probably easiest to mount it on the underside of the NES motherboard.
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

viletim wrote:Lopenator and jkuch77,

There's a metastability bug in the NESRGB V4, it prevents/corrupts palette updates so colours go wrong. I think it should be possible to avoid it by changing the timing of the appropriate signal a little bit.

Try this: connect a small ceramic capacitor between pin 13 of the PPU (CE#) and ground. Some value between 22p and 56p should be good. It's probably easiest to mount it on the underside of the NES motherboard.
Is a capacitor like this acceptable?

https://www.mouser.com/ProductDetail/Bo ... z3oA%3D%3D
Last edited by Lopenator on Thu Oct 06, 2022 10:14 pm, edited 1 time in total.
jkuch77
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Re: NESRGB board available now

Post by jkuch77 »

Lopenator wrote:
viletim wrote:Lopenator and jkuch77,

There's a metastability bug in the NESRGB V4, it prevents/corrupts palette updates so colours go wrong. I think it should be possible to avoid it by changing the timing of the appropriate signal a little bit.

Try this: connect a small ceramic capacitor between pin 13 of the PPU (CE#) and ground. Some value between 22p and 56p should be good. It's probably easiest to mount it on the underside of the NES motherboard.
might sound like a dumb question but does p mean pF? Also does voltage value matter?
I installed a 47pF ceramic cap (470 stamped on it) that I had lying around between pin 13 and ground of the PPU as suggested. The color issue appeared immediately after loading a game from the everdrive, but after a reset it was fine and I played for about 20 min without the color issue happening. Also, loaded a different game and played for about 10 min. So far so good it looks like. I have to go to bed now, but I will play much longer tomorrow and let you know if the issue returns.
jkuch77
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Re: NESRGB board available now

Post by jkuch77 »

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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

jkuch77 wrote:
Is a capacitor like this acceptable?

https://www.mouser.com/ProductDetail/Bo ... z3oA%3D%3D
This is the one I used: https://www.digikey.com/en/products/det ... kAiIAugL5A
Thanks. I'll order this one. I want to confirm it actually works too. On my NES it has taken 2 hours before the colors changed on me. Sometimes 5 minutes too though.
viletim
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Re: NESRGB board available now

Post by viletim »

jkuch77 wrote:
Lopenator wrote:
viletim wrote:Lopenator and jkuch77,

There's a metastability bug in the NESRGB V4, it prevents/corrupts palette updates so colours go wrong. I think it should be possible to avoid it by changing the timing of the appropriate signal a little bit.

Try this: connect a small ceramic capacitor between pin 13 of the PPU (CE#) and ground. Some value between 22p and 56p should be good. It's probably easiest to mount it on the underside of the NES motherboard.
might sound like a dumb question but does p mean pF? Also does voltage value matter?
I installed a 47pF ceramic cap (470 stamped on it) that I had lying around between pin 13 and ground of the PPU as suggested. The color issue appeared immediately after loading a game from the everdrive, but after a reset it was fine and I played for about 20 min without the color issue happening. Also, loaded a different game and played for about 10 min. So far so good it looks like. I have to go to bed now, but I will play much longer tomorrow and let you know if the issue returns.
It might me a good idea to try a 100p, or possibly even a 220p capacitor instead. Ideally, the wrong colour symptom should not occur at all once the cap in installed.

On the PAL top loader I have which has the same problem, I found it had to be at a particular temperature to occur. Too cold or too hot it didn't happen. Once I put the cap on the CE# signal it never happened again.
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

If it's not too much of a hassle, maybe you can send a link of recommended capacitors to buy for us to try. Not sure which ones to pick.
viletim
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Re: NESRGB board available now

Post by viletim »

Lopenator wrote:If it's not too much of a hassle, maybe you can send a link of recommended capacitors to buy for us to try. Not sure which ones to pick.
Perhaps buy a couple of each of these.

CAP CER 47PF 50V C0G/NP0 RADIAL
https://www.digikey.com/en/products/det ... TL2/286463

CAP CER 100PF 50V C0G/NP0 RADIAL
https://www.digikey.com/en/products/det ... TL2/286467
jkuch77
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Re: NESRGB board available now

Post by jkuch77 »

jkuch77 wrote:I installed a 47pF ceramic cap (470 stamped on it) that I had lying around between pin 13 and ground of the PPU as suggested. The color issue appeared immediately after loading a game from the everdrive, but after a reset it was fine and I played for about 20 min without the color issue happening. Also, loaded a different game and played for about 10 min. So far so good it looks like. I have to go to bed now, but I will play much longer tomorrow and let you know if the issue returns.
viletim wrote:It might me a good idea to try a 100p, or possibly even a 220p capacitor instead. Ideally, the wrong colour symptom should not occur at all once the cap in installed.

On the PAL top loader I have which has the same problem, I found it had to be at a particular temperature to occur. Too cold or too hot it didn't happen. Once I put the cap on the CE# signal it never happened again.
I just played Super Mario Bros. for about only 15 min just now and the color issue did happen again after about 10 min. I will try the larger cap and post back my results.
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Lopenator
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Re: NESRGB board available now

Post by Lopenator »

I just ordered a couple of 50pf and 100pf caps. When they come in I'll update also.

Is there a ground next to the pin 13/CE signal so I'm not running a wire all the way across?
jkuch77
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Re: NESRGB board available now

Post by jkuch77 »

Lopenator wrote:I just ordered a couple of 50pf and 100pf caps. When they come in I'll update also.

Is there a ground next to the pin 13/CE signal so I'm not running a wire all the way across?
Pin 20 of the PPU is ground and is what I used. I don't have any of the larger caps, so just ordered a few of the 100p and 220p caps, so will be a few days before I can update also.
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