NES mod questions (power and regulation, cartridge slot etc)

[jaqiefox]

intro: skip this if you wanna get to the meat of the post
Hey all. Been reading here for a few days, just found this forum a few days ago. I have been a long time pc tech (16 years) and cartridge console fan, and just recently got bit by the console collect and mod bug, few months ago when I found a fully functional but wore out NES with zelda inside it in the dumpster at my apartment. I have since collected an snes, a genesis, and two atari 2600s and just getting warmed up. I have done a lot of jerry rigging over the years, but nothing beyond physical work, I do not understand transistors and beyond, but do understand resistors, diodes, capacitors, and such perfectly, along with my dremel and casemodding.

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the meat:
I have an original NES which has the standard problem of the cart connector wearing out. I am fine with modding it and know how, but I wonder a few things.

Would taking the 72 pin crap-connector out, slicing off the part that USED to accept the cartridge, modding the connector to accept a cartridge where the NES board used to plug into it, and soldering it to the NES work at all? or is the conductor pitch or plug itself incompatible? I am not afraid of xacto knives or dremels at all.

The internal electric requirements are 5V DC, right? If so, how tight does it need to be regulated? Personal Computer (PC) ATX power supply spec says +-5% voltage and pretty tight transient regulation is what PCs need... is the NES similar in requirements? I am not asking about using an ATX PSU, im asking if the kind of regulation used for pc parts is adequate for an NES or does it need even tighter reg? (this is assuming I wire the power directly into the board after the onboard regulator!)

I did some homework and found out that the NES 72 pin connector is 2.5mm pitch and the normal connectors sold for PC and many other things are 0.1" pitch (2.54mm pitch)... does this create a problem using a 0.1" (2.54mm) pitch connector for a nes cartridge? anyone?

does anyone know a good place to buy inexpensive dogbone NES controllers? not third party, used actual ones... ive had my fill of crappy made third party controllers.

[jdmlight]

the meat:
I have an original NES which has the standard problem of the cart connector wearing out. I am fine with modding it and know how, but I wonder a few things.

Would taking the 72 pin crap-connector out, slicing off the part that USED to accept the cartridge, modding the connector to accept a cartridge where the NES board used to plug into it, and soldering it to the NES work at all? or is the conductor pitch or plug itself incompatible? I am not afraid of xacto knives or dremels at all.

The internal electric requirements are 5V DC, right? If so, how tight does it need to be regulated? Personal Computer (PC) ATX power supply spec says +-5% voltage and pretty tight transient regulation is what PCs need... is the NES similar in requirements? I am not asking about using an ATX PSU, im asking if the kind of regulation used for pc parts is adequate for an NES or does it need even tighter reg? (this is assuming I wire the power directly into the board after the onboard regulator!)

I did some homework and found out that the NES 72 pin connector is 2.5mm pitch and the normal connectors sold for PC and many other things are 0.1" pitch (2.54mm pitch)... does this create a problem using a 0.1" (2.54mm) pitch connector for a nes cartridge? anyone?

does anyone know a good place to buy inexpensive dogbone NES controllers? not third party, used actual ones... ive had my fill of crappy made third party controllers.

1. That could work. I know that many people seek out cartridge connectors from the Game Genie or from clones. Either of these options may work better with less work.

2. The NES isn't super-picky about its +5v power, a simple 7805 regulator is common. In fact, that's what is in the original power supply of the NES. I would imagine that if you were concerned about it, having +5v to ATX specs would be fine.

3. Yes, pitch matters. That seemingly-small amount of difference means that if you line up the connector with the first pin on the cartridge, as you go down, the rest of the pins will become farther and farther off. I know there was talk of a certain cartridge connector on Digi-Key working for the NES, but I don't remember which one off hand. I'll look to see if I can find that thread. EDIT: Found it! "http://www.digikey.com/ has a card edge connector that should work with NES carts, part # A31721-ND."

4. The only place I'd know to check would be eBay. It looks like original Nintendo dogbone controllers are running about $20 there.

It sounds like you're at least planning on replacing the cartridge connector. Now that you've made us all curious, what other mods are you looking into for your NES?

[jaqiefox]

1. That could work. I know that many people seek out cartridge connectors from the Game Genie or from clones. Either of these options may work better with less work.

I guess Ill open it up and look closely then. I wonder if this will actually be doable!

2. The NES isn't super-picky about its +5v power, a simple 7805 regulator is common. In fact, that's what is in the original power supply of the NES. I would imagine that if you were concerned about it, having +5v to ATX specs would be fine.

Awesome! I have switching type 5v wall warts coming out of my ears, that are made for direct attachment to hard drives and such.... much more power efficient than the old analog ones, and if I can cut down EFI/RFI enough I can put them inside the device and not only run a normal cord to it, but also make a real power switch that cuts off the transformer when not in use! (I like being energy efficient, just how I am)

3. Yes, pitch matters. That seemingly-small amount of difference means that if you line up the connector with the first pin on the cartridge, as you go down, the rest of the pins will become farther and farther off. I know there was talk of a certain cartridge connector on Digi-Key working for the NES, but I don't remember which one off hand. I'll look to see if I can find that thread. EDIT: Found it! "http://www.digikey.com/ has a card edge connector that should work with NES carts, part # A31721-ND."

But... that's just the problem! did you look at that part number? it's got a 0.1" (2.54mm) pitch, not 2.5mm like the NES cartridge has!......

4. The only place I'd know to check would be eBay. It looks like original Nintendo dogbone controllers are running about $20 there.

hm.... little rich, but I guess beggars can't be choosers. I was hoping to find them for $10-15 shipped

It sounds like you're at least planning on replacing the cartridge connector. Now that you've made us all curious, what other mods are you looking into for your NES?

Well, I am thinking original NES, but thinner, just making it as tall as the dark grey bottom or such... slot load vertically into the rear of the top panel... also like I mentioned removing the old wall wart for something much more efficient... then stereo mod but with crossfeed adapters (they are popular with the audiophile headphone crowd, and can fix the stereo separation oddness issue if you stereofy the nes)... I also wanna do the overclocking switch thing... and maybe mod in my wireless 4-player adapter (nes sattelite) direct into the NES as well.

I also definitely want an original gen2 toploader bad and then do the av mod and some of what I listed here to that as well.

[jdmlight]

Awesome! I have switching type 5v wall warts coming out of my ears, that are made for direct attachment to hard drives and such.... much more power efficient than the old analog ones, and if I can cut down EFI/RFI enough I can put them inside the device and not only run a normal cord to it, but also make a real power switch that cuts off the transformer when not in use! (I like being energy efficient, just how I am)

Be careful with those though, measure the actual output with a multimeter. Many aren't regulated, and will put out quite a bit more than 5v, even though they say 5v on them. Though if you're like me and have a large pile of leftover power bricks, it's likely that you'll find one that is regulated.

But... that's just the problem! did you look at that part number? it's got a 0.1" (2.54mm) pitch, not 2.5mm like the NES cartridge has!......

Oops, my bad. That's what I get for copy-pasting between threads. I'd say finding a Game Genie or clone would be your best bet then. I'm planning on using a Game Genie in my it'll-be-done-eventually NES portable. Like this Game Genie for $10 shipped, for example: http://www.ebay.com/itm/Nintendo-NES-Ga ... 2eb7cccc1c

hm.... little rich, but I guess beggars can't be choosers. I was hoping to find them for $10-15 shipped

Can't hurt to post a WTB thread here in the Trading Post forum.

Well, I am thinking original NES, but thinner, just making it as tall as the dark grey bottom or such... slot load vertically into the rear of the top panel... also like I mentioned removing the old wall wart for something much more efficient... then stereo mod but with crossfeed adapters (they are popular with the audiophile headphone crowd, and can fix the stereo separation oddness issue if you stereofy the nes)... I also wanna do the overclocking switch thing... and maybe mod in my wireless 4-player adapter (nes sattelite) direct into the NES as well.

I also definitely want an original gen2 toploader bad and then do the av mod and some of what I listed here to that as well.

Fun fun fun. I thought the stereo mod typically had a potentiometer that adjusted the amount of separation? I could be wrong though. In which case, a crossfeed adapter would work well. I'd recommend trying out varying amounts of crossfeed with higher/lower value resistors. With something like the NES, where the signal isn't meant to be stereo, you may want a lot more of the left channel/right channel mixing than most people building a crossfeed adapter for headphones. As an example, the crossfeed adapter I built for my headphones doesn't mix the channels very much at all, but it provides the desired effect for that purpose.

[Metallica Man X]

hm. You do need a set of pots for the stereo mix. The stereo mod I have set up on my commission NES mixes quite nicely with two separate 1k pots. The central lead of the pots goes to the NES, one lead of each pot hooks to a lead on the other pot, and the remaining leads go to the amps.

[jaqiefox]

Yeah, I planned on making sure it was regulated, this is why I brought up the ATX spec.

It seems I won't be needing a game genie or such after all, the 72 pin connector needed some heavy modding but it will work wonderfully for this provided I don't slip and ruin it in the process. >.<

It seems you're right about the cross-fading, I hadn't realized that is what those were for.

I also have a picture of my connector mod in progress, I decided to take a break while fixing my damn cheap (bought from amazon for $4 shipped) wire strippers busted, using gorilla glue to mend the black plastic piece which snapped just between the lower jaw and big wheel looking thing on the part just to the left of the soldering gun tip in this picture.

My dremel is the 400 XPR version, I used to *HATE* dremels, and then I saw this one in a starter kit at the local bi-mart store (kinda like a small town version of a micro walmart) for $50... and I love it! It's the most powerful they ever made, and it has replaceable motor brushes, along with being a permanent magnet motor, meaning if you stall this thing it's YOUR fault. And yes, that is a weller 140w/100w transformer/nichrome element soldering gun. I love this thing, and have a somewhat unique technique which makes it safer to use around electronics then most, but it requires a practiced hand.

[jdmlight]

I <3 my 400XPR. It is so far superior to the older one my dad has (that I was using for a while).

Whee pictures! Pictures are always appreciated.

[jaqiefox]

End of day one.



I have tentatively decided to put the NES into an old motorola surfboard cablemodem shell instead of going back into the NES shell, the NES motherboard was much smaller then I remember them being, and I like the idea of having it in a small vertical box with the game cartridge sticking out of the top.

On the left is the new power cable and plug salvaged from the same surfboard modem, I will use an ATX power supply switch on the back of the cablemodem for the NES power switch.

Just to the right of those in the foreground is a wall wart which came from a cheap usb hub, and another just like it just beside it which has been taken out of the shell. This is a regulated 120VAC to 5VDC regulated supply which can do about 400mA. I chose this for its efficiency, and its size. It also has a power LED on it for some reason

Then you can see the 72 pin connector with me having started soldering wires to it. The wire I am using comes from another item I found with the NES in the local dumpster when I took out trash, a defunct xmas light set - the wire from those things is always very handy to have lots of, and you can't beat the price! It's even some form of copper alloy.

Then you can see that I removed the RF adapter from the NES board along with removing the expansion port, thus making it rather sleek and small. It almost fits in the motorola insides right now, though it is a bit too "deep" (the long side is too long) so I figure I will dremel off some of the shielding interface on the board, being careful not to go too far and cut traces.


end day 1... I think I got a lot done considering my wire strippers broke

[Metallica Man X]

Interesting....that modem box will make the NES look pretty Wii-ish lol.

I look forward to seeing if the original cart connector's base can be used as a main cart connector

As for KIA wire strippers...you still got your teeth, right?

[jaqiefox]

not posting to whine, just to let those that showed interest know:

I used to work on computers for a living, like I said... I am now disabled, numerous problems, two forms of arthritis, ANS, EDS, porphyria, and the big nasty one: MSA... been taking my usual arthritis meds along with my emergency vicodins and still not really able to do much, which is why this is on hold till I am doing better.

Again, just letting folks interested in what im doing know what's up, and that it will continue - my interest in this has actually grown since I started this, really wanna get it done.

[Metallica Man X]

Dang

That's pretty weak. I hope you get better soon.

[jaqiefox]

small update, big pics. too tired/sore to resize them.

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http://foxtecha.com/pics/consoles/nes/mod1/100_0949.JPG" onclick="window.open(this.href);return false;
http://foxtecha.com/pics/consoles/nes/mod1/100_0950.JPG" onclick="window.open(this.href);return false;

Dremeled the edges off the board so it would fit, pulled off the blue housing for the nes front switch assembly, bent back the nes controller plug, dremeled out the metal so the power switch and ac plug would fit and hotglue fit them in, size testing the nes board.

[jaqiefox]

Waiting on parts to build this since I removed the original RF box.

[low_budget]

The digi key cart connector (A31721-nd) isn't exactly the same pitch as the original, but it's so close I found it to work just fine.
Also, you don't need to duplicate the original composite boost circuit, a 2n4401 transistor and a couple resistors works well also.
I used a adjustable voltage regulator circuit from ebay for my NES dialed in to 5.1v.
hope this helps

[jaqiefox]

Thanks for the answer on the 0.1" pitch connector issue. that will help with future projects for sure!

I want the best video out possible within reason, and this circuit was recommended to me by a very technical friend over the simple resistor and transistor video amp circuit as being a decent amount better, so I am going to go with it.

if it was set to 5.1v then chances are the adjustable VR was actually producing something else, unless you "dialed it in" with a meter instead of with calculations. those things have a tolerance (usually 5%) just like all other electronics.

Thanks for the post! Im glad someone had reliable info on the connector, that will help a good bit.