NESRGB board available now

[TheRetromancer]

Those are diodes, not resistors. Diodes are often used in rectifier circuits.

Any ideas what rating they are??

Hah! Like I thought, the bridge rectifier blew.

Can't tell what the diodes are from your pictures. See if you can get in there and tell what color bands are on the good diodes, and in what order. The only NES schematic I've found has text too small to read on the bridge rectifier, but it seems to read "BA20 x4" or "DA20 x4". What makes it worse is that there are two types of frontloader power supplies - one that uses an RC203 bridge rectifier, and then the one you have, which uses discrete diodes. I have the RC203 model, and I haven't been able to turn up any info on replacing the discrete model version. I wonder if it's possible to 'drop-in' an RC203 if you make sure to align the polarity of the legs properly? Helpfully, the power module itself shows which polarity each diode is right beneath the component.

[ms06fz]

With the Analogue Nt announced today as being a bit more than I'm willing to pay for, I'm back to looking at this RGB board again. Is there any word on when they'll be back in stock? I want to be sure I jump on it while I can.

I asked Tim about this via email and he answered me a few days ago, says that he's waiting on some parts. (Sounds like they're hung up in customs or something?) He wasn't able to give a precise answer because it basically depends on when he gets those parts.

Hopefully that email notification thing on the shop website works as advertised. Just in case it doesn't, I've taken to reloading the item page multiple times a day to see if NESRGB is back in stock yet.

[ms06fz]

Honest to god, I've got nothing. All the standard possibilities (accidental solder bridge, power surges, component failures) seem to be ruled out by your other modded NES. I mean, unless you somehow hit upon a one-in-a-million way of installing the NESRGB board that would let it work for a bit and THEN fry something (which I strongly doubt), I am at a total loss to explain what's happening.

My only other course of action would be to try plugging into a different wall socket - who knows?

Ok it gets weirder, I stumbled upon that if i inserted the spike volleyball cart without pushing it down in the locked position then the NES powered up fine, as soon as i pushed the cart down i lost all power, this is the same for all 3 NES consoles!.

You can see the burn mark on the pcb, guess that was the bad one then....

Would could have caused this to happen?

OK, hard to be too sure of what's going on without some hands-on time with these consoles, but here's a theory...

First, the cartridge, when plugged in, is like any other part of the system - the system doesn't have a lot of protection for the CPU, power supply, etc. when a cartridge draws too much power or applies too much voltage to something. The problem here may be as simple as a cartridge drawing too much current.

One possible explanation for why a cartridge might draw too much current is a short circuit, perhaps caused by "tin whiskers". (Over time, solder joints accumulate mineral deposits - little "whiskers" of metal growing off the solder joint. If "whiskers" grow too much, it can result in a short circuit. Tin whiskers are less common with leaded solder, which I think was still commonly used in production electronics in the late 1980s/early 1990s... But it's one possibility.) It could also be that one of the ROM chips got zapped in a way that produced a short circuit - I don't know how likely either scenario is... Or maybe someone altered this cart in the past and screwed it up?

If there were a short circuit in the cartridge's power supply pins, it would draw more and more current from the power supply until something fails. In this case, the rectifier diodes. If you were using an AC power supply, you might have seen all four rectifier diodes fail, but because you were using a DC power supply, only two of them (the ones passing current) failed.

As for the humming - I'm still not sure. If you blew out half of your rectifier using a DC supply then switched to an AC supply, your NES would get voltage for only half of the AC phase (so roughly 1/120 of a second of power, then power off for 1/120 of a second, etc., assuming the regulator circuit/capacitor isn't able to smooth that out) - that could almost certainly account for the "buzzing". You'd expect to hear a 60 Hz tone, which is pretty low, but you might hear higher pitches as well depending on what sound the NES makes during that 1/120 of a second of "on" time.

You might open up the cartridge and take a look, see if the solder joints look like they have "whiskers". It's also possible that the cartridge was just flat-out fried at some point, and this somehow resulted in a short-circuit path across one of the ROM chips' power pins or something. If you're not able to find a solution, I'd be wary of trying this cart in any more systems. Next time it might kill more than the power supply...

As for replacing the diodes - there are two ratings you have to concern yourself with: current limit and breakdown voltage.
Current limit is how much current you can put through the diode before it is in danger of blowing up. This needs to be higher than the amount of current your NES will use. (Somewhere around 1A-1.5A I think? It should be printed on the system. Bear in mind that NESRGB takes additional power as do items like everdrive carts.)
Breakdown voltage is how much voltage the diode can block - this should be higher than the voltage of any power supply you'll use with the system. (I'd say go for at least 25V, even though you're probably not gonna use a power supply greater than 10V)
Just search for "rectifier diode" and you'll get some decent candidates.

[TheRetromancer]

1.5 is the way you want to go - the PSU outputs 1.3A, and there's no way you want to put any component in-line with amperage that it isn't rated for.

Yeah, 25v tolerance is overkill, but that won't harm anything. I always prefer identical or as near-to as I can get for repairing old systems. Your local Radioshack or equivalent should be able to help you out there. Just be absolutely sure that you mount the diodes in CORRECTLY - the cathode (-) end has a white marking around it, and should always go into the hole nearest to the vertical line of the 'diode symbol', NOT the side that is near the arrow.

[mvsfan]

yeah and while your at it you probably want to re-cap the nes. cap kits are available at console5.com.
it makes no sense not to because the nes is at least 25 years old and if your caps arent leaking now, they will soon enough.

If you dont do all of them, at least replace the BIG cap.

as a side note - Ive noticed that the caps used in the nes were very good. I dont run into too many nes's where they are all leaking.

The snes on the other hand the caps used in it are not as good as the ones in the nes almost every snes is leaking now to some degree.

[TheRetromancer]

yeah and while your at it you probably want to re-cap the nes. cap kits are available at console5.com.
it makes no sense not to because the nes is at least 25 years old and if your caps arent leaking now, they will soon enough.

If you dont do all of them, at least replace the BIG cap.

as a side note - Ive noticed that the caps used in the nes were very good. I dont run into too many nes's where they are all leaking.

The snes on the other hand the caps used in it are not as good as the ones in the nes almost every snes is leaking now to some degree.

I've never had a cap problem with any SNES, ever. I have eight SNESes and ten SFCs, and I've never had a single problem with them related to the caps.

[lettuce]

1.5 is the way you want to go - the PSU outputs 1.3A, and there's no way you want to put any component in-line with amperage that it isn't rated for.

Yeah, 25v tolerance is overkill, but that won't harm anything. I always prefer identical or as near-to as I can get for repairing old systems. Your local Radioshack or equivalent should be able to help you out there. Just be absolutely sure that you mount the diodes in CORRECTLY - the cathode (-) end has a white marking around it, and should always go into the hole nearest to the vertical line of the 'diode symbol', NOT the side that is near the arrow.

Seem to find loads that are 1A rated and all the way up to like 50V but not 1.5A anywhere. The ones ive found are 3A and about 35v, there the 1N5400 series....

http://www.vishay.com/docs/88516/1n5400.pdf

will the 1N5400 do the trick?

The only thing i could see on the diodes left in the NES was U8 printed on the diode itself

[TheRetromancer]

Shouldn't be a problem. It's a bit beefy for the application, but there's just that much more headroom available.


A good thing to remember with electronics is that in most applications, it's okay to ramp up the tolerances of components. But never, under any circumstances, should you use underrated components. That's just asking for trouble.

[lettuce]

Ok ill get some of the 1N5400 diodes then, its probably best if i replace all 4 just to be on the safe side.

Opened up the cart and notice the burn mark on the inside of the case and the browned legs of the 1MC3B chip.....



not sure why that happened!?

[leonk]

oh wow!!

NES carts operate at 5V DC. For the MC3 mapper to get that damaged, it got a heck of a lot more than 5V .. probably as much as line voltage (110V!!) You can short all the wires on the mapper, and never get that kind of damage from 5V.

That TLROM PCB is toast.

[TheRetromancer]

oh wow!!

NES carts operate at 5V DC. For the MC3 mapper to get that damaged, it got a heck of a lot more than 5V .. probably as much as line voltage (110V!!) You can short all the wires on the mapper, and never get that kind of damage from 5V.

That TLROM PCB is toast.

Holy shit. That must have been a VISIBLE arc when that thing went to shit. You are lucky nothing on the NES got fried.

[Ed Oscuro]

probably as much as line voltage (110V!!)

Well, that's 230V for the UK.

[lettuce]

oh wow!!

NES carts operate at 5V DC. For the MC3 mapper to get that damaged, it got a heck of a lot more than 5V .. probably as much as line voltage (110V!!) You can short all the wires on the mapper, and never get that kind of damage from 5V.

That TLROM PCB is toast.

Holy shit. That must have been a VISIBLE arc when that thing went to shit. You are lucky nothing on the NES got fried.

Well i wont know if the NES is dead or not until i get some replacement diodes.

Im starting to wonder if it was the NESRGB that caused this, as this is the first NESRGB (done 4 in the past) where i have used the NES own regulator and not the supplied one that comes with the NESRGB. I think thats what might have cause all this, that just sending the full 230v to the cart slot, not sure how or why though...is that even possible at all?

I have another 2 NES's here but im not sure i want to try this NESRGB in those 2 system incase it does the samething again, thats if it is the NESRGB that cause the burn out

[mvsfan]

I've never had a cap problem with any SNES, ever. I have eight SNESes and ten SFCs, and I've never had a single problem with them related to the caps.


IF you break one of those caps off even on a board that looks good, I almost guarantee they are leaking out through the bottom where you cant see it yet. It tends to collect in the plastic foot at the base of the cap first.

[TheRetromancer]

I'm not going to say it's impossible that it was the NESRGB board, but I really think it was more likely that the gods of random chance and douchebaggery decided to kick you in the teeth, and the components that were designed to fail upon a problem in order to protect more vital components...did. A couple of diodes are nothing to replace.

Yeah, it sucks that a game got crispified, but at least it wasn't a $150 game. When my cousin's SNES blew during a thunderstorm, he was playing Mega Man X3. I still have that cart, and it still makes me a bit teary.

IF you break one of those caps off even on a board that looks good, I almost guarantee they are leaking out through the bottom where you cant see it yet. It tends to collect in the plastic foot at the base of the cap first.

I've measured every single cap, and they all show proper values. Even if they go phut, they won't damage the board, and no sense in replacing them if there's no need.

[Ed Oscuro]

A quick check online suggests that some people have seem primarily shorts in failed diodes, which would do it.



I would hope they would have failed open-circuit instead.

[K-2]

Had Jason over at Game-tech.us mod a top-loader for me. This the top-loader running through a XRGB-mini in Meister using scart. Looks awesome haven't tried it with my BVM yet, I imagine it will look ace on that too.

[juji82]

If I get an AV Famicom and mod it, Can I use this cable or I will need to mod it? It is the official RGB Gamecube Cable from Nintendo.

[LaC]

If I get an AV Famicom and mod it, Can I use this cable or I will need to mod it? It is the official RGB Gamecube Cable from Nintendo.

I believe these cables have 75 ohm resistors and 220uf caps in them. The NESRGB board already has that on there. So you either need to jump those, or remove the caps from the scart cable. The latter is easier, but then won't work on a snes/gc.
If you do nothing, it will still work, you will just have to adjust the brightness on your monitor/tv to compensate for the extra resistors darkening the image.

[juji82]

so.. I will not get a dropped image quality, just brightness, right? So I should get a normal scart cable or ask Tim to dump those from Nesrgb board maybe

[LaC]

so.. I will not get a dropped image quality, just brightness, right? So I should get a normal scart cable or ask Tim to dump those from Nesrgb board maybe

You can request a scart cable from retrogamingcables.com that doesn't have the extra components in them. Or from retro_console_accesories as well.
I didn't notice a drop in image quality. But, I jumped them on the board. Didn't make sense to keep them there when every cable I would ever use would already have those components in them. And it was annoying to change brightness all the time on my well calibrated display.

[airs]

DOL-013 works with my NESRGB modded front loader (with multiout mod). Looks great.

[lettuce]

I'm not going to say it's impossible that it was the NESRGB board, but I really think it was more likely that the gods of random chance and douchebaggery decided to kick you in the teeth, and the components that were designed to fail upon a problem in order to protect more vital components...did. A couple of diodes are nothing to replace.

Yeah, it sucks that a game got crispified, but at least it wasn't a $150 game. When my cousin's SNES blew during a thunderstorm, he was playing Mega Man X3. I still have that cart, and it still makes me a bit teary.

Damn X3 of all the games, was that back in the 90s or more recently now its a £150+ game?

Whats the easiest way to test the NESRGB to make sure it's still function correctly?, hopefully the installed PPU wasnt fried in the process as well as they are a bitch to remove once soldered onto the NESRGB, I almost wish that it was socket design for easy removal

[darcagn]

Damn X3 of all the games, was that back in the 90s or more recently now its a £150+ game?

They pretty much run for the same price as the sd2snes premium flash cart that supports nearly every ROM, including Mega Man X3 and its Cx4 chip.

[viletim]

Well i wont know if the NES is dead or not until i get some replacement diodes.

Im starting to wonder if it was the NESRGB that caused this, as this is the first NESRGB (done 4 in the past) where i have used the NES own regulator and not the supplied one that comes with the NESRGB. I think thats what might have cause all this, that just sending the full 230v to the cart slot, not sure how or why though...is that even possible at all?

I have another 2 NES's here but im not sure i want to try this NESRGB in those 2 system incase it does the samething again, thats if it is the NESRGB that cause the burn out

That cartridge looks like it has been damaged by over voltage. I presume it worked before... So I suspect the NES and NESRGB are also damaged. Did you connect anything to the power supply or modify it somehow? It's not possible to have mains/230V inside the NES as the transformer in the AC adapter provides isolation, but even 9V AC would cause ICs to burn.

If you need a replacement NESRGB board please send me an email. Reduced price for disaster victims.

If I get an AV Famicom and mod it, Can I use this cable or I will need to mod it? It is the official RGB Gamecube Cable from Nintendo.

You can just use it as-is. I don't think the extra capacitors in the cable will cause any problem.

How's your routing from the NESRGB to the mini din for the svideo? Is it going over any IC's or tangled up in any other wires that could cause interference?

To eliminate any possible interference issues, I terminated both chroma and luma from the NESRGB Y/C outputs with shielded cable.

Obviously poor cables can have a profound effect on signal quality. But I don't understand why an official SNES S-Video cable would be insufficient, whilst it's plenty efficient for the SNES, N64, and Gamecube consoles.

It sounds like you've ruled out the cable... The only thing I can think of is there may be a poor ground connection between your NESRGB board and video cable. Check that it's well soldered.

[Skips]

Not enough original Famicom love in this thread. Here is one I finished for myself last night. I took a page out of Bakutendo's book and filed the RF port and switch holes larger for an SNES style AV port. Unfortunately that means you cant get the hole snug around the AV port as the original RF hole is higher that the AV port. Still though it looks better than leaving a gaping round hole in the system. I also used the Channel switch as the palette switch. The system is only wired for the PC10 palette and the original palette. It is by far not my cleanest work but its not bad and works very well. Only RGB and S-Video are connected

[Voultar]

Skips, I really like how you handled the controller cabling coming from the back of the Famicom. The Multi-Out was very well done, too. I did something quite similar to my Twin Famicom during the NESRGB installation.

I correctly removed the proprietary controller connectors from the Famicom mainboard, and terminated the through-holes with headers.



And then I ran the NES extension cabling throughout the back, just as you did with the Famicom. The only difference being the cable length.



Very well done!

[lettuce]

Well i wont know if the NES is dead or not until i get some replacement diodes.

Im starting to wonder if it was the NESRGB that caused this, as this is the first NESRGB (done 4 in the past) where i have used the NES own regulator and not the supplied one that comes with the NESRGB. I think thats what might have cause all this, that just sending the full 230v to the cart slot, not sure how or why though...is that even possible at all?

I have another 2 NES's here but im not sure i want to try this NESRGB in those 2 system incase it does the samething again, thats if it is the NESRGB that cause the burn out

That cartridge looks like it has been damaged by over voltage. I presume it worked before... So I suspect the NES and NESRGB are also damaged. Did you connect anything to the power supply or modify it somehow? It's not possible to have mains/230V inside the NES as the transformer in the AC adapter provides isolation, but even 9V AC would cause ICs to burn.

If you need a replacement NESRGB board please send me an email. Reduced price for disaster victims.

Yeah the cart worked fine before this mishap .

What the best way for me to test the NESRGB to see if it is fried or not?, im guessing the PPU will also be dead on the NESRGB also then?

On a side note, i have found some 1.5A diodes (1n5391)....

http://www.ebay.co.uk/itm/351041628193

will that be fine for the NES?

[TheRetromancer]

Yeah the cart worked fine before this mishap .

What the best way for me to test the NESRGB to see if it is fried or not?, im guessing the PPU will also be dead on the NESRGB also then?

On a side note, i have found some 1.5A diodes (1n5391)....

http://www.ebay.co.uk/itm/351041628193

will that be fine for the NES?

I can't see anything that would cause a problem with those diodes. Let us know how it goes!

[leonk]

As far as I understand it VERY BAD IDEA. The NES creates DC from AC using bridge ractifier using diodes. The power input is 110V/220V AC with output being DC. It is then converted to 5V DC using the power regulator. A big cap is included to make the AC pulses smooth for DC.

My point? Those eBay diodes are only rated for 50V!! You'll blow them.

Well i wont know if the NES is dead or not until i get some replacement diodes.

Im starting to wonder if it was the NESRGB that caused this, as this is the first NESRGB (done 4 in the past) where i have used the NES own regulator and not the supplied one that comes with the NESRGB. I think thats what might have cause all this, that just sending the full 230v to the cart slot, not sure how or why though...is that even possible at all?

I have another 2 NES's here but im not sure i want to try this NESRGB in those 2 system incase it does the samething again, thats if it is the NESRGB that cause the burn out

That cartridge looks like it has been damaged by over voltage. I presume it worked before... So I suspect the NES and NESRGB are also damaged. Did you connect anything to the power supply or modify it somehow? It's not possible to have mains/230V inside the NES as the transformer in the AC adapter provides isolation, but even 9V AC would cause ICs to burn.

If you need a replacement NESRGB board please send me an email. Reduced price for disaster victims.

Yeah the cart worked fine before this mishap .

What the best way for me to test the NESRGB to see if it is fried or not?, im guessing the PPU will also be dead on the NESRGB also then?

On a side note, i have found some 1.5A diodes (1n5391)....

http://www.ebay.co.uk/itm/351041628193

will that be fine for the NES?