N64 RGB DIY mod looks smeary, looking for some help

[raskulous]

Good morning.

I did my N64 RGB mod last night using the 7316 amp, but the results are looking very smeary. There's a bunch of mis-coloured streaks coming off the right hand side of everything.

Photos here - > https://imgur.com/gallery/9kh1rm5

I took apart the mod afterwards and double-checked everything, and soldered it back together, only to get the same result.

Any ideas?

Thanks!

[raskulous]

Oh, one more thing about my setup.. the A/V from the N64 is going through an Extron matrix switch, then gets converted with a Shinybow SCART -> Component converter before running to my TV.

[dibmem]

Your board appears to be wired correctly, as long as those resistors are 75ohm...
I'll take a try at assisting - A couple of questions:
What's the N64 board revision? (NUS-CPU-0x?)
What are you using for sync from the N64 to your Shinybow converter? (Are you using a luma or composite sync SCART cable?)

[raskulous]

The board is a NUS-CPU-03, and the cable is a retrogamingcable.uk N64 cable that uses CSYNC.

Maybe my board doesn't have CSYNC to pin 3 of the multi-out? How do I check that?

[Link83]

The NUS-CPU-03 should have LVTTL level CSYNC still connected to pin 3, but what components are on the CSYNC line inside the SCART cable?
If you have the option/ability I would be tempted to use Sync on Luma instead if you can.

[raskulous]

I'm not sure what's in the cable, as I didn't make it, but I ordered a CSYNC cable from them to allow for use with my Extron, and all other cables I have from them are CSYNC. I'd have to contact them for more details if I need.

The trouble is, that the Extron will not work with Sync on Luma.

[Syntax]

The Extron matrix can take any level of sync, it will reclock and buffer it to 4.5v TTL.

Do you have a 480R resistor on the matrix csync output to your TV?

[raskulous]

I'm not sure.

Out of the extron is a BNC to SCART cable that I purchased, that goes into my Shinybow SB-2840, so I'm not sure what's in it.

To be fair, I have about 8 consoles ruining through it, and it to the shinybow and they're all fine, which leads me to believe that this is an issue with the n64 or the mod somehow, and not the Extron, cables, or shinybow.

I tested the N64 with my SNES SCART cable, and it looks exactly the same.

I tested my N64 cable with my SNES, and it looks great.

[dibmem]

I don't see anything incorrect on your 7316 install.
The legs are all oriented correctly for RGB, correct 75 Ohm resistors and 0.1uf Capacitor in the right place.
After I posted, I realized I could see all the parts populated for csync on the board, so that shouldn't be it...
If you had a sync issue, you wouldn't get a stable picture typically, not something smeary.

So that leads me to believe something else in the chain isn't happy with what's being put out by your N64.
Any other cables or output devices to test with? (HD Retrovision / OSSC?)
Have you bypassed the Extron to see if the smearing is occurring there?

[raskulous]

Does anyone know how to check if a model NUS-CPU-03 N64 is actually outputting CSYNC to pin 3 on the Multi-out? It seems that some have it, and some don't.

If it's not, it seems like this mod would be able to help.

http://www.mmmonkey.co.uk/console/downl ... 0csync.pdf

[raskulous]

I don't see anything incorrect on your 7316 install.
The legs are all oriented correctly for RGB, correct 75 Ohm resistors and 0.1uf Capacitor in the right place.
After I posted, I realized I could see all the parts populated for csync on the board, so that shouldn't be it...
If you had a sync issue, you wouldn't get a stable picture typically, not something smeary.

So that leads me to believe something else in the chain isn't happy with what's being put out by your N64.
Any other cables or output devices to test with? (HD Retrovision / OSSC?)
Have you bypassed the Extron to see if the smearing is occurring there?

I don't really have any other devices to test, but I will definitely bypass the extron and see if that makes any difference. I'll get back to you on that.

Thanks for the enlightenment on the sync.. if I can rule that out due to the picture being stable, that is a big help.

[raskulous]

I will definitely bypass the extron and see if that makes any difference. I'll get back to you on that.

Okay, N64 -> SCART out -> Shinybow -> TV

Same result, albeit a little less noisy now.. maybe my 75 ohm resistors aren't high enough quality? They are +/-5% as far as I can tell (gold band).

[Josh128]

Check them if you have a DMM. if they are within 5-7 ohms they should be fine. Do you have a way to check your caps?

That white bleed to the right looks very similar to the white bleed I get from RGB on my original SNES console. Makes me wonder if theres some bad caps somewhere in the video circuit in the console itself that are causing this.

[Josh128]

Does anyone know how to check if a model NUS-CPU-03 N64 is actually outputting CSYNC to pin 3 on the Multi-out? It seems that some have it, and some don't.

If it's not, it seems like this mod would be able to help.

http://www.mmmonkey.co.uk/console/downl ... 0csync.pdf

If your SCART cable doesnt have anything wired to pin 3 on the N64 side, you can open the connector, move the composite wire to that pin, and if you get sync, the console has it. Mine has it.

[raskulous]

Check them if you have a DVM. if they are within 5-7 ohms they should be fine. Do you have a way to check your caps?

That white bleed to the right looks very similar to the white bleed I get from RGB on my original SNES console. Makes me wonder if theres some bad caps somewhere in the video circuit in the console itself that are causing this.

They're all bang on 75ohms according to my meter. If the caps were bad, wouldn't the signal also look poor on other signals? It looks perfectly fine on S-Video with a cheap aftermarket cable, as well as composite.

[rama]

The chip might be bad. Especially consider this if you've got it from China in a cheap 5 pack.

[raskulous]

The chip might be bad. Especially consider this if you've got it from China in a cheap 5 pack.

Hmm, I guess it wouldn't hurt to order some more, they are dirt cheap. I got it free from a friend that ordered a cheap 5 pack from china, but as far as I can tell, it's an actual Texas Instruments brand, but who knows..

[maxtherabbit]

make sure the component legs or whatever you used to anchor to the RGB vias aren't poking through the other side of the board and shorting to an encoder leg

[raskulous]

make sure the component legs or whatever you used to anchor to the RGB vias aren't poking through the other side of the board and shorting to an encoder leg

I did that, and even took it apart once and re-did it to be sure.

[Josh128]

Check them if you have a DVM. if they are within 5-7 ohms they should be fine. Do you have a way to check your caps?

That white bleed to the right looks very similar to the white bleed I get from RGB on my original SNES console. Makes me wonder if theres some bad caps somewhere in the video circuit in the console itself that are causing this.

If the caps were bad, wouldn't the signal also look poor on other signals? It looks perfectly fine on S-Video with a cheap aftermarket cable, as well as composite.

Not necessarily. My SNES 1 does exactly that, great looking S-Video and white bleed on RGB. This is why your issue is reminding me so much of my SNES 1 issue. I bet what ever is causing it is related. See below.

S-Video: https://i.imgur.com/aP5qVlf.jpg

Native RGB: https://i.imgur.com/yV3wPaD.jpg

[raskulous]

Interesting. I'll keep that in mind after changing out the amp, thanks!

[dibmem]

Does anyone know how to check if a model NUS-CPU-03 N64 is actually outputting CSYNC to pin 3 on the Multi-out? It seems that some have it, and some don't.

If it's not, it seems like this mod would be able to help.

http://www.mmmonkey.co.uk/console/downl ... 0csync.pdf

That circuit rebuilds csync on a board that is lacking it altogether. You don't need to do that since you have the circuit / components in place on your 03 board.
R15 / R16 / Q1 and a few others are all missing on 04 boards and they can be seen on your install photos.
* Edit * Huh - I just compared an 03 and 04 board. If you have the letter "S" next to pin 3, you have csync. The letter isn't even screened onto 04 boards.
You can check continuity from pin 3 on the multi-out to C22 which is the last stop in the circuit... No cap there, no csync.

I doubt that your encoder is fault - I always use a short length of wire from R8/R9/R10 to the input side of the 7314/6 though, rather than using legs directly to the vias.

I have an 03 board here - Perhaps I'll wire it up like yours to see if it's something with this specific board, rather than your install method or components you used.

Edit: Completed construction of board and installation.
No problems with smearing, sync, or functionality with my NUS-CPU-03 system through the OSSC + csync is confirmed working with a PVM.
Here's how I wire mine:
https://imgur.com/Up9X8VS

[Josh128]

Any progress on this?

[raskulous]

Yes, sorry for the late reply..

I mentioned earlier that the setup looks fine on the SNES, leading me to believe that it was the N64 that was the issue. I finally had some time to spare to look into this again, and my Genesis was outputting the same smearing!

Turns out it was only a faulty component cable (the one that runs from my Shinybow to the TV), and it was intermittently causing issues.. which is why my SNES looked good, and the N64 looked bad.

Anyway, replaced the component cable, and everything is perfect now. Thanks everyone for your input!