NESRGB board available now

[viletim]

Is it safe to remove this?

I'm not going to use the RF or any of the switches on this board.

It's safe to remove. I recommend disabling the RF modulator entirely to reduce the interference to the video signal and NESRGB operation. Removing the two transistor in the metal box should do it.

Hey all,, I'm hoping someone might be able to point me in some direction for this problem I started having just recently. I'm using a second batch NESRGB in a US toploader, of which I had one of the chips replaced because of the whole error that was in the second batch. Every now and then I would have a garbled image on the screen while playing, at first I thought it was all just from having dirty connections on the cart pin connections (because it would go away after reinserting the cart a couple times), but after polishing everything up it still happens,.

This is currently what I am getting off my NES http://i.imgur.com/OFWdqzu.png (This is the castlevania intro)

That screencap was taking just after I had replaced the SRAM, WRAM, CPU, and PPU with parts from a working toaster I had lying around. to be more precise I had the console open turned it on to test it, and got another garbled image, but it fixed itself shortly after and then went back down hill after a few minutes of playing. Does anyone have any ideas of what might be the problem?

If the audio continues to work and game plays then it's porbably CHR bus data corruption - there's a bad connection somewhere. As a first step I would resolder pins 23-39 on the NESRGB and adapter. It's not related to the RAM chip in the NESRGB as that only stores colours.

Does the problem go away if the NESRGB is removed and the PPU is replaced in its original position?

[Jeppen]

Is it safe to remove this?

I'm not going to use the RF or any of the switches on this board.

It's safe to remove. I recommend disabling the RF modulator entirely to reduce the interference to the video signal and NESRGB operation. Removing the two transistor in the metal box should do it.

Thanks for the reply.

I removed it plus the 2x blue circled things (See pic)
Famicom now gave no picture.

I Put back the 2x "blues", but flipped them on the backside to make room.
Still no picture.

I removed the 2x transistors as suggested.
Still no picture.

I can't put back the Original thing with the metal casing, as i kind of ruined it in the desoldering process (didn't notice it had 2x legs in the back still soldered and pulled it out)

It was working perfectly before i desoldered anything (The TV-Game switch was already removed and the Famicom was still working great)


Any idea what could have gone wrong?

[keropi]

^ the only thing you need from that board is the LM7805 that powers the famicom and it's filtering caps, everything else can be removed.
This is how I have modified my famicom:



only the power supply stuff are left and the red wires are GND/VCC lines (audio and video ones that went to the RF encoder are desoldered), nothing else is needed to get a picture if you have a composite mod (like mine) or a NESRGB like you have...

[Einzelherz]

When I was pulling parts out of the RF box on my front loader NES I just made sure to trace only parts that were connected directly to the RF jack itself. Go over the traces and see if any of the legs you've removed were in line with the power or whatever else is in there on a Famicom.

[Jeppen]

Thanks!

Strange that mine stopped working, it still gets power as i put in a power LED and this lights up as normal.
Just not getting any picture.

hmmmm

*edit*

I connected it again to the Framemeister and now it worked perfectly, i think it was a glitch in the power switch solders

[TechyTom]

If the audio continues to work and game plays then it's porbably CHR bus data corruption - there's a bad connection somewhere. As a first step I would resolder pins 23-39 on the NESRGB and adapter. It's not related to the RAM chip in the NESRGB as that only stores colours.

Does the problem go away if the NESRGB is removed and the PPU is replaced in its original position?

The audio worked just fine and I managed to figure out the problem. When I tried to remove the whole board from my top loader when I had it first installed I ended up bending a few of the header pins and I guess because of that I get some connection errors from to PPU back to the NES. I mostly fixed the issue by tinning a few of the header pins and sucking most the solder off of them(so they could still be place into the sockets), which seems to have helped a lot. I still get a few moments where stuff pops onto the screen that shouldn't be there but it usually goes away shortly, or a quick reset fixes it.

[cfx]

^ the only thing you need from that board is the LM7805 that powers the famicom and it's filtering caps, everything else can be removed.
This is how I have modified my famicom:



only the power supply stuff are left and the red wires are GND/VCC lines (audio and video ones that went to the RF encoder are desoldered), nothing else is needed to get a picture if you have a composite mod (like mine) or a NESRGB like you have...

May I suggest replacing the two electrolytic caps in your power circuit? I see those are Lelon, which I unfortunately have a lot of experience with leaking. They're one of the companies that used that stolen faulty electrolyte formula years ago. I've had them bulge and leak even on boards that were never used.

[keropi]

Sadly lelon caps are all I can get here... It was my understanding that now their caps are ok, I even see them in networking gear and Sony stuff... Certainly not the best choice but they don't die that easily anymore
My reasoning for changing them is that after 25 years the original caps are surely worse than mid-quality new ones

[Einzelherz]

I've got a peculiar situation. I threw together a SCART RGB converter for my PSone LCD, mostly out of boredom, and I've been testing it with my systems. The Genesis and SNES look great on it, but my NES is acting strange in a couple of ways.

First, blues aren't quite their correct shade. This is particularly evident in Final Fantasy where the menu colors are blue normally (pure blue, I think) but are showing up black. Other colors that contain blue seem messed up, but I've checked the connectivity from the NES input to the PSone LCD input and it's ok.

The other is more confusing to me. When you plug the screen in by itself, it powers on. But when you hook up a system to it the screen turns itself off because it's not getting a +5 volt feed (I think). Except with the NES. The screen stays on the whole time. Maybe I'm misremembering but I thought someone had said the NESRGB's +5v doesn't work correctly. I wouldn't notice this normally because my YUV converter ignores that pin.

Any guesses would be greatly appreciated.

[TechyTom]

Einzelherz-

I'm not very knowledgeable about the subject either, but do you think it could have anything to do with the resistors and capacitors already in line on the NESRGB?

[Einzelherz]

Einzelherz-

I'm not very knowledgeable about the subject either, but do you think it could have anything to do with the resistors and capacitors already in line on the NESRGB?

I don't think so since they'd just be inside the cable on the other systems.

[Jeppen]

^ the only thing you need from that board is the LM7805 that powers the famicom and it's filtering caps, everything else can be removed.
This is how I have modified my famicom:



only the power supply stuff are left and the red wires are GND/VCC lines (audio and video ones that went to the RF encoder are desoldered), nothing else is needed to get a picture if you have a composite mod (like mine) or a NESRGB like you have...

This is some awesome and valuable info!!

Where did you find that 60 pin cart connector?
It doesn't look quite original, but it's blue and with the "wings", i've been looking for one, but can only find a black one without the wings, but this looks very similar to yours with the actual pins.

[keropi]

@Jeppen

I did not change the card slot, if I am not mistaken blue color is common in famicoms...?
If you do a google image search for "famicom motherboard" you will see many blue slots

[kamiboy]

What the deuce. I just finished with my first front loading NES installation of the board thinking that the provided RGB connector was meant to work with the Mega Drive 2/CDX SCART cables. After finding my cable I discovered that it does not fit because it has one pin too many.

What is this port designed to work with?

Also, anyone knows where the voltage input pin of the NES regulator? Tim, your installation guide needs a bit of work.

[Einzelherz]

The installation guide worked well for the rest of us. It even shows you where the VIN pin is.

[kamiboy]

Yeah, on the external regulator, but which leg on the 7805 on the NES?

[Jeppen]

Yeah, on the external regulator, but which leg on the 7805 on the NES?

Is this what you are looking for?

[Jeppen]

@Jeppen

I did not change the card slot, if I am not mistaken blue color is common in famicoms...?
If you do a google image search for "famicom motherboard" you will see many blue slots

Ah ok, i see now that there are a few slightly different production versions around.

[Jeppen]

I bought 2x NESRGB (second batch if it matters).

One is installed in a European Frontloader, the other in a 1983 Japanese Famicom.

Both share the same problem of faint flickering in the background of some colors, it looks a lot like a power issue/interference.

Has anybody had the same problem?

I'm starting to wonder if it is the NESRGB external voltage regulator that is the crook here,
has anyone tried another external volt reg other than the one from Tim and seen a difference?

[kamiboy]

Yeah, on the external regulator, but which leg on the 7805 on the NES?

Is this what you are looking for?

Sure is, thanks. By the way, is installing the regulator really desperately needed or is it just a precaution on the front loading NES? I didnt bother with it on my AV Famicom and it works fine, same deal here?

[ApolloBoy]

After finding my cable I discovered that it does not fit because it has one pin too many.

What is this port designed to work with?

It's an 8-pin mini-DIN which matches the Framemeister's RGB input jack.

[kamiboy]

Well, faux pas on my part for making an assumption. Such a port is useless for my purpuse but I sure as deuce am not going to undo all that work.

[mufunyo]

Both share the same problem of faint flickering in the background of some colors, it looks a lot like a power issue/interference.

Has anybody had the same problem?

I have this problem, for me it seems to be related to the fact the NESRGB board assembly (the adapter board + NESRGB board) is mounted with round pin headers in a socket instead of square pin headers, which comes loose very easily. When I get the interference, tapping the shell (lol Russian method) fixes the problem temporarily. The NESRGB stupidly easily becomes dislodged from its socket. Next time I'll get square pin headers just for this very reason.

[cyborc]

I bought 2x NESRGB (second batch if it matters).

One is installed in a European Frontloader, the other in a 1983 Japanese Famicom.

Both share the same problem of faint flickering in the background of some colors, it looks a lot like a power issue/interference.

Has anybody had the same problem?

I'm starting to wonder if it is the NESRGB external voltage regulator that is the crook here,
has anyone tried another external volt reg other than the one from Tim and seen a difference?

are you using an xrgb mini? I've noticed this using my NTSC front loader on the mini and im not using the extra voltage reg. When I played it on a CRT I didn't notice any flickering.

[ApolloBoy]

Next time I'll get square pin headers just for this very reason.

Actually it's best not to use square pin headers for connecting the NESRGB to the NES/Famicom motherboard. I used them when I installed an NESRGB in my Twin Famicom, and the square headers wound up bending out the DIP socket pins to the point where the NESRGB would fall out if the console got even a little jostled. I switched it all out for round pin headers and a machined socket and all is well now.

[keropi]

Anyone knows if there are H and V separate signals anywhere available on the NESRGB?
(no idea if they exist on the nes/famicom at all , I want to try and build a sync combiner like on the DC that worked wonders with my framemeister)

Also, is there any ETA on the component addon?

[kamiboy]

No, c-sync already gives you combined sync.

[ApolloBoy]

no idea if they exist on the nes/famicom at all

Well no since it normally only has composite video.

[keropi]

No, c-sync already gives you combined sync.

I know but it does not work for me with the framemeister... that's why I am looking to try stuff
looks like this is a dead end...

[antron]

No, c-sync already gives you combined sync.

I know but it does not work for me with the framemeister... that's why I am looking to try stuff
looks like this is a dead end...

there are lots of things to try. basically your framemeister does not like the c-sync the NESRGB creates using its "comparators"? make your own by running the PPU composite video through a LM1881 or EL4581. Or run the NESRGB composite video through them.

If you really want to make C-sync from some H and V syncs you can get H from the LM1881 and make V with an XOR of C and H. But this just sounds crazy.

But doesn't the NESRGB kit use a framemeister pinout? Wasn't the point of this so it would be easily compatible? How is this not working?