Twin famicom NESRGB color problem

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VEGETA
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Joined: Mon May 31, 2021 10:40 am

Twin famicom NESRGB color problem

Post by VEGETA »

Hello,

please check the graphical glitch here: https://imgur.com/a/EwtkP6b

This is after doing nesrgb (also checked by official distro)... it was working fine as I remember but done some cap replacements then found it to be like this. some games are glitches free like megaman 3.

I tested faulty games on another twin famicom (which was labelled as "not confirmed" but works) via composite on CRT and they work without a problem!

could this be my PPU (despite being checked by the distro guy and found to be ok)? I mean replacing it could solve the problem? I cannot replace the whole board since the modded one is Blue+Black model while the other one is black+red which has different power buttons.

I eventually want to get N8 Pro but I am afraid it will show same problems too, the system should work regularly first.

Is there anything I can test?

I do remember putting the system to show disc system animation (insert disc..etc) and it has the faults but when moving the board around it gets changed and sometimes fixed. this is typically traces issue but none of this movement worked when in cartridge mode.

Last act is to get another blue+black twin famicom but would like to try if switching the ppu works or not.

NOTE: super mario world 3 doesn't start just by power button, but requires me to press reset.

please help
Last edited by VEGETA on Sun Jun 26, 2022 7:08 pm, edited 1 time in total.
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Syntax
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Re: Twin famicom NESRGB color problem

Post by Syntax »

Is the palette switch installed correctly?
If it is not set up correctly you end up with glitches similar to what you are showing.

Whilst doing the cap replacement you may of disconnected a switch wire?
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VEGETA
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Re: Twin famicom NESRGB color problem

Post by VEGETA »

Syntax wrote:Is the palette switch installed correctly?
If it is not set up correctly you end up with glitches similar to what you are showing.
hmm the pallet is hard soldered to neutral, plus it worked on other games.

also, what switch wire? can you point out where it is?
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VEGETA
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Re: Twin famicom NESRGB color problem

Post by VEGETA »

it is worth mentioning that super mario world 3 doesn't start by activating the power button, but always requires me to press the reset button. this wasn't the case before.

i am not 100% sure, but I think everything worked well before cap replacement. what could do such damage!?
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Syntax
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Re: Twin famicom NESRGB color problem

Post by Syntax »

" If no palette is selected the NESRGB board will 'turn off' and just pass data through. This way the NES will output composite video as if the board was not installed at all."

If you try run RGB with the palette set to neutral/off you will have glitches like that.

Test the composite video output and see if its fine?
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VEGETA
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Re: Twin famicom NESRGB color problem

Post by VEGETA »

Syntax wrote:" If no palette is selected the NESRGB board will 'turn off' and just pass data through. This way the NES will output composite video as if the board was not installed at all."

If you try run RGB with the palette set to neutral/off you will have glitches like that.

Test the composite video output and see if its fine?
I meant it is selected to be the normal\neutral color pallet... meaning "3" is soldered\bridged to gnd. I have removed composite jack to make room for my plugs.

I will post some pics now, stay tuned.
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VEGETA
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Re: Twin famicom NESRGB color problem

Post by VEGETA »

I think I made it to work somehow. I spent HOURS enhancing the solder and so on, really didn't do anything new.

Then I tested the cartridges and they started working again after wiggling them and lifting 1mm from here and 0.5mm from there until they touch perfectly. Captain Tsubasa 2 and Mario used to have glitches, now gone. all games are working fine now.

I suspect one cap had a problem, I wiggled the 0.47uF one near reset button a lot during testing which gave different results until it worked. it is not 100% confirmed to be the issue but suspect it is.

anyway, I think now I can get N8 Pro and wiggle the shit out of it until it fits then just let it be forever.

BTW, the power button plastic piece which was missing I replaced it with a small paper xD.
Vodkanakas
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Joined: Wed Oct 26, 2022 11:34 pm

Re: Twin famicom NESRGB color problem

Post by Vodkanakas »

Hi did you ever figure out the problem here i installed my v3.0 resently and came across this same issue. I replaced the caps on the reset circuit with no change.
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