Help with N64 RGB and checkboarding

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mobiusau
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Joined: Wed Jul 29, 2020 6:53 am

Help with N64 RGB and checkboarding

Post by mobiusau »

Hi,

So i just installed arthrimus's N64 RGB board (the rev with integrated 3.3v regulator) into my NUS-CPU-03 NTSC-J (VDC-NUS) 64

Install went fine, solder joins look good and no bridging ect. However I've fired the system up and tested a few games and noticed a lot of checker-boarding specifically on Mario Kart 64/Super Mario 64

Is this normal? bad joins?, bad 64 board? issues with the RAD2x?

RAD2x cable is connected to a Samsung 55" QA55Q7FNA

https://imgur.com/a/HutCaDy
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Link83
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Re: Help with N64 RGB and checkboarding

Post by Link83 »

Have you disabled/removed the N64's original CSYNC signal? (Assuming your using AV port Pin 3 for CSYNC) Also what type of CSYNC output has it been configured for, TTL or 75ohm?
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

Link83 wrote:Have you disabled/removed the N64's original CSYNC signal? (Assuming your using AV port Pin 3 for CSYNC) Also what type of CSYNC output has it been configured for, TTL or 75ohm?
I followed his install guide on YouTube (apart from using the MAV-NUS adapter board, since i have a VDC-NUS so i wired the cables to the pin legs are per the outputs)

So i have not disabled CSYNC, however i don't believe its required? No idea on the CSYNC output again i don't believe i can adjust that?
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Link83
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Re: Help with N64 RGB and checkboarding

Post by Link83 »

The NUS-CPU-03 is the last N64 motherboard revision to have CSYNC output still connected on the AV port. If you have connected the RGB boards CSYNC output to Pin 3 without freeing up the pin first, then that can lead to problems.

The Arthrimus board listed here:-
https://arthrimus.com/product/universal ... regulator/
Appears to have different output pads so you can choose between 75ohm (CS75) or TTL (CS) CSYNC outputs.

Which CSYNC output type have you used, and which AV port pin has it been connected to?

<EDIT> Out of curiosity, since you have a revision with the VDC-NUS chip is there a reason why you choose not to use the basic RGB amp?:-
https://arthrimus.com/product/borti4938 ... 4-rgb-amp/
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

Link83 wrote:The NUS-CPU-03 is the last N64 motherboard revision to have CSYNC output still connected on the AV port. If you have connected the RGB boards CSYNC output to Pin 3 without freeing up the pin first, then that can lead to problems.

The Arthrimus board listed here:-
https://arthrimus.com/product/universal ... regulator/
Appears to have different output pads so you can choose between 75ohm (CS75) or TTL (CS) CSYNC outputs.

Which CSYNC output type have you used, and which AV port pin has it been connected to?

Also, out of curiosity is there a reason why you choose not to use the basic RGB amp?:-
https://arthrimus.com/product/borti4938 ... 4-rgb-amp/

<EDIT> Out of curiosity, since you have a revision with the VDC-NUS chip is there a reason why you choose not to use the basic RGB amp?:-
https://arthrimus.com/product/borti4938 ... 4-rgb-amp/
[/quote]

Ahh completely missed that.

I've wired to the TTL CSYNC output type, not sure what AV port in has been connected to as i just used his AV break outboard.

https://youtu.be/NxGIhH4mSoI?t=1618

The seller i got my N64 from sent me the wrong model :) I was expecting a MAV chipset as he had originally told me he was out of ealry rev 64's
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Link83
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Re: Help with N64 RGB and checkboarding

Post by Link83 »

Well I cant be certain as I cant find photos of both sides of that AV breakout board on the website, but its very likely connected to Pin 3.

If you look at the back of the N64 motherboard you should see a trace running from capacitor C22 up to the AV port. If you want to remove the original CSYNC signal you need to very carefully cut that trace, or if you dont feel confortable cutting that trace you would need to remove some surface mount components to free up AV port Pin 3.

Nintendo themselves removed six surface mount components on the NUS-CPU-04 revision to remove CSYNC output (R15, R16, Q1, R1, R14, C22) but I dont think its really necessary to remove them all just to disable CSYNC, but I couldn't say which ones in particular are critical to break the circuit.

I think Arthrimus is fairly active around here, so you could also wait for their input/suggestions.
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

Link83 wrote:Well I cant be certain as I cant find photos of both sides of that adapter on the website, but its very likely connected to Pin 3.

If you look at the back of the N64 motherboard you should see a trace running from capacitor C22 up to the AV port. If you want to remove the original CSYNC signal you need to very carefully cut that trace, or if you dont feel confortable cutting that trace you would need to remove some surface mount components to free up AV port Pin 3.

Nintendo themselves removed six surface mount components on the NUS-CPU-04 revision to remove CSYNC output (R15, R16, Q1, R1, R14, C22) but I dont think its really necessary to remove them all just to disable CSYNC, but I couldn't say which ones in particular are critical to break the circuit.

I think Arthrimus is fairly active around here, so you could also wait for their input/suggestions.
Did some quick googling and correct me if i am wrong but i can just remove R14 and that should disable the CSYNC output? and removing the rest of the components is not required?

Also i guess i can breath a bit easier since my issues might just be interference and not my poor soldering skills......

Haven't soldered since high school (10 years ago now) and over the weekend i did the PS-IO install (with Voultar's wonderful SIO-X board), Arthrimus's SNES RGB/Dejitter board and his N64 RGB board :)

Thank god both have YouTube video's so i can teach myself how to solder (without burning my house or consoles down)
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Link83
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Re: Help with N64 RGB and checkboarding

Post by Link83 »

mobiusau wrote:Did some quick googling and correct me if i am wrong but i can just remove R14 and that should disable the CSYNC output? and removing the rest of the components is not required?
I think R14 may be enough, but I genuinely cant remember as its been so many years since I last looked into this. I also dont know if leaving C22 in place could cause any issues, since it would stilll be connected to Pin 3 and the other side connects to ground.

Glad the modding is working out for you :) It can be quite a rewarding experience when you get everything working.
makar1
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Re: Help with N64 RGB and checkboarding

Post by makar1 »

The RAD2X doesn't connect to Pin 3/CSYNC so it shouldn't be causing issues. It only takes sync from the composite video pin.

You could try replacing composite video with CS75 (75ohm level CSYNC) to get a cleaner sync signal to the RAD2X.
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Link83
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Re: Help with N64 RGB and checkboarding

Post by Link83 »

I'm not familiar with the RAD2X, but even if it doesn't use Pin 3/CSYNC, having two TTL level CSYNC outputs connected together could lead to all sorts of issues/interference problems. It might not necessarily be the cause of the problem, but it would be best to start from a correct configuration so we can at least rule it out before looking elsewhere.

I guess if the RAD2X doesn't use the CSYNC pin you could just remove the CSYNC wire from between the RGB board/AV Port, if only for testing purposes. However if you would still like the option to use a CSYNC SCART cable in future, then you really only want one of the two CSYNC outputs connected to Pin 3 - either the original N64's CSYNC or the RGB boards CSYNC (I'm guessing that the RGB boards De-blur/15bit Color mode abilities would only work if using the RGB boards CSYNC output, which would make that the preferred CSYNC option)
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

Ended up removing the components for CSYNC and no difference!. The checkerboard affects are still visible on the red/blue backgrounds in Mario Kart 64 and Super Mario

I know in YouTube video the red backgrounds look clear with no checker boarding, guess this is a possible RAD2x issue?

How do i connect CS75 up? Do i run a wire from Pin 9 to CS75 on the RGB board and remove the wire running from pin 3?
makar1
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Re: Help with N64 RGB and checkboarding

Post by makar1 »

mobiusau wrote: How do i connect CS75 up? Do i run a wire from Pin 9 to CS75 on the RGB board and remove the wire running from pin 3?
You can do the same series resistor removal to temporarily disable composite video output, and directly wire CS75 to the composite pin 9 of the AV out. From the schematics available online it looks like resistor R5, but verify yourself on your board.

CS75 is CSYNC but attenuated to the same voltage level as the sync signal carried by composite video. The RAD2X only detects sync from the composite pin, so you can only use pin 9.
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

makar1 wrote:
mobiusau wrote: How do i connect CS75 up? Do i run a wire from Pin 9 to CS75 on the RGB board and remove the wire running from pin 3?
You can do the same series resistor removal to temporarily disable composite video output, and directly wire CS75 to the composite pin 9 of the AV out. From the schematics available online it looks like resistor R5, but verify yourself on your board.

CS75 is CSYNC but attenuated to the same voltage level as the sync signal carried by composite video. The RAD2X only detects sync from the composite pin, so you can only use pin 9.
Pulled composite from PIN 9 to the CS75 pad on the board and bingo no more checkerboarding!.

Now i am running a RAD2x cable on my 1Chip with the RGB bypass and dijitter, i am going to assume the CSYNC i am using for this mod is also just TTL and i should redo it to pull the signal from composite?
makar1
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Re: Help with N64 RGB and checkboarding

Post by makar1 »

If the image is clean without modifying the default composite video output I'd leave it alone. The RGB bypass boards only seem to have TTL level CSYNC that needs to be attenuated before using it to replace sync-on-composite.
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

Hmm so i checked the image output on the SNES alot closer and yep checkerboarding on Mario and Toads hat/head.

So do i just remove the wire i have running from R9 to CS on arthrimus's board and instead have PIN 9 run to CS? (or do i run it to the LL CS pad?)

https://imgur.com/bEFJRRg

edit: Did some more reading and correct me if i am wrong (my knowledge of electronics is very rusty) i need to place a 330ohm resistor inline, i cannot just run the wire direct?

Does it matter how many watts the resistor is?
makar1
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Re: Help with N64 RGB and checkboarding

Post by makar1 »

The SNES RGB bypass boards don't provide CS75 as they're usually used to restore TTL CSYNC for SNES models that don't support it natively. You'll need to use a resistor to connect CS from the RGB board to Pin 9, after disconnecting composite video.

330ohm is commonly used for SNES CSYNC attenuation as the TTL voltage is lower than other consoles where 470ohm is used. Wattage shouldn't matter as the current flow is very small for video signals.
Ikaruga11
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Re: Help with N64 RGB and checkboarding

Post by Ikaruga11 »

Link83 wrote:The Arthrimus board listed here:-
https://arthrimus.com/product/universal ... regulator/
Appears to have different output pads so you can choose between 75ohm (CS75) or TTL (CS) CSYNC outputs.
Is this the same thing as Borti's N64 Advanced board?
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

GeneraLight wrote:
Link83 wrote:The Arthrimus board listed here:-
https://arthrimus.com/product/universal ... regulator/
Appears to have different output pads so you can choose between 75ohm (CS75) or TTL (CS) CSYNC outputs.
Is this the same thing as Borti's N64 Advanced board?
No. It is more like Borti's N64 V2 board
Ikaruga11
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Re: Help with N64 RGB and checkboarding

Post by Ikaruga11 »

mobiusau wrote:
GeneraLight wrote:
Link83 wrote:The Arthrimus board listed here:-
https://arthrimus.com/product/universal ... regulator/
Appears to have different output pads so you can choose between 75ohm (CS75) or TTL (CS) CSYNC outputs.
Is this the same thing as Borti's N64 Advanced board?
No. It is more like Borti's N64 V2 board
Ah, okay. Thanks. This doesn't have the 15 bit color mode, does it? Does Borti's N64 Advanced have the Integrated 3.3v Voltage Regulator that this has?
mobiusau
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Re: Help with N64 RGB and checkboarding

Post by mobiusau »

GeneraLight wrote: Ah, okay. Thanks. This doesn't have the 15 bit color mode, does it? Does Borti's N64 Advanced have the Integrated 3.3v Voltage Regulator that this has?
Arts' board has the de-blur and the 15 bit colour mode features. (de-blur is OK for some games, makes other look terrible and for me the 15 bit colour doesn't do THAT much)

I believe the Advance does have a voltage regulator. Its more similar to an UltraHDMI (line-doubling, on-screen menu) which means you get a much nicer image, however you are paying almost double compared to Art's board or Borti's V2 board

If you have the $$$ get the Advance, otherwise art's board with the 3.3v regulator is just as good as Borti's V2 board (I have both and image difference between the ths7374 (used in art's) and adv7125 (used in Borti's V2) is nothing.

Art's univeral board is generally cheaper then Borti's V2 board (again depending on where you source Borti's boards from)
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