nesdev.org

teaguecl wrote:I can't think of a reason, other than as a repair of a damaged one. In that case, it's way easier to just pull a CIC from an old cartridge.

Well, you could install it in a console and have universal region switching cic just like Super CIC for the SNES. But then again, if you were to open the console to install it, might as well just cut pin #4 and ground it...

if the pin #4 mode doesn't work on your nes you could just patch it with a key from a "blob top" super mario bros/duck hunt or wait a little longer for my release... ciclones are $4.. SMB/duck hunt 25 cents.. avr is around $0.40-$1.50 i believe that $4.00 ciclone doesn't include shipping

EDIT1/2: it also doesnt support "lock" mode

you would basically need to clip the input pin and hook a key up to the clock, in, out, vcc and ground

nintendo was planing on embedding 10nes into the memory mappers but didn't until SNES.. (cost maybe) the only flaw without the back door is the fact that you can hard-wire a key to the lock but big N knew that... but people back then didn't know much about the "magic" of digital electronics..

if you use a fine set of wire cutters.. or maybe one of the "mini fordable sowing scissors sets" you can cut pin #4 on the lock near the board and wire it to ground (or let it float) if it doesn't work just solder the wire to vcc and the sytem will still function.. or just pull the whole CIC chip and patch the circuit


the circuit above is what i came up with when the pin #4 mod locked me out.. originally thought to be a damaged chip.. we now know it doesn't work that way on all CIC's.. the circuit also works with copynes.. encase someone is wondering about that long reset it needs

nintendo could of had 100,000 CIC's with the back door present so they mixed 100,000 without it ... that would explain why CIC's in the consoles always had the exact same part number. but in the game carts they have different revisions.. (speculation)

it could be a case of hit and miss.. out of about 10 NES's 3 didn't have the back door
the first was one i tried to mod and the other two i tested after they being pulled .. all my nes's have patched boards.. wanted the chips for testing...

someone PM me if something in this posts is out of wack and all touch it up a little

EDIT2/2: thought i should point out that the jumper in the center of the photo does exactly the same thing as the green jumper in the diagram/schematic

EDIT3:

SkinnyV wrote:I don't quite get what's ''not working'' about the pin-4 to ground mod... Everybody that tried know that it does work. Maybe it was badly phrased?

maybe tepples could change the thread name for me i don't know if it would start a new thread if i change it or not..
thread name should be "pin #4 mod doesn't work on all CIC's" ..

it works for most people but all the people thinking they destroyed the CIC could actually have one of the chips it doesn't work for
how does someone screw up cutting pin 4? not that you can't damage it but i've heard of a lot of people messing that up

Jeroen wrote:There were some cics that only operate as keys iirc. So you'd have to make sure it's not one of those.

a lock can unlock a lock
a key can unlock a lock
a key can unlock a key (in lock mode)
a lock can NOT unlock a key (in lock mode)

it only effects 611x/b revision chips because of timing
hope i didn't leave anyone out send me a PM if i missed your question

OK, so please bear with me as I know a little bit about electronics repair (I own and maintain several arcade cabinets) but not much at all about the NES. I have two systems, one is the original NES I got for Christmas 84 (or 85) and one I just picked up at a yard sale. The one I've owned my whole life is still pretty bulletproof (need to wiggle the games a bit to make them work but it's not much hassle, and all games eventually play). The one I picked up at the yard sale I tested out and it had a lot of trouble getting games to play on it. So, I did some research and found out about the pin4 mod, as well as replacing the 72 pin connector.

I ordered a replacement connector, and while waiting for it to arrive, I disassembled and cleaned the yard sale NES, and performed the pin4 mod by snapping the leg (if this is the problem, I can blame myself for being too lazy to get out the desoldering iron instead). The new connector arrived, I put it on my shiny clean NES, and fired it up, except... I quite often get a blank gray screen. Many games boot up perfectly the first time (Maniac Mansion, Metroid to name two), but several games (Kirby's Adventure with perfect contacts) just refuse to boot no matter what I do. I put KA into the old NES and it boots up fine, first try.

So, my understanding of the electronics in this thread is minimal, but does my experience seem to relate to what you're saying about the pin4 mod? Do I need to replace my CIC chip (or otherwise patch the circuit) to get games like KA to boot again?

If you guys think my system helps confirm the theory of the pin#4 mod not always working, is there any data about my system I can provide to help figure it out?

Edited to add: My original NES is 100% original, no mods, no replacements, never even been opened (although I probably will replace the 72 pin connector at some point). The yard sale one I've only had for about a week.

No, that's just the program not booting because the games are dirty. Clean the games with alcohol or something better, and then also maybe the connector in the system somehow to get the dirt off that was on those dirty games.

3gengames wrote:No, that's just the program not booting because the games are dirty. Clean the games with alcohol or something better, and then also maybe the connector in the system somehow to get the dirt off that was on those dirty games.

As I said, the game itself has perfect contacts and boots just fine in my original NES... thanks for the input, though.

If it turns out my issue has nothing to do with this topic, please forgive me and I'll start my own thread.

edited to add: and the connector is brand new, as I said...

Doesn't matter what it LOOKS like, the games are 25 years old, there is plent of caked on thin layers of dirt on those connectors. The game isn't booting, something is dirty. Unless it's your "new" connector, it's the game. Clean it with an eraser and then alcohol after, I'd bet a lot that'll make it work.

3gengames wrote:Doesn't matter what it LOOKS like, the games are 25 years old, there is plent of caked on thin layers of dirt on those connectors. The game isn't booting, something is dirty. Unless it's your "new" connector, it's the game. Clean it with an eraser and then alcohol after, I'd bet a lot that'll make it work.

I guess I could've been more clear: the game has been cleaned, that's what I meant by "perfect" contacts. Works 100% of the time in the old stock NES. Works 0% of the time in modded NES with new connector and pin 4 CIC mod.

I'd make sure the system connector is making good contact, re-seat it, and clean the board connector too is what I'd guess. And also maybe make sure no pins popped out, I had that happen when I put in a game in on my Ninja Grip system. No way is it related to the pin 4 mod, no way, it's just a standard bad connection. The solid screen means the program isn't starting up, and the lockout has no effect on what the CPU is doing, outside of resetting it.

3gengames wrote:I'd make sure the system connector is making good contact, re-seat it, and clean the board connector too is what I'd guess. And also maybe make sure no pins popped out, I had that happen when I put in a game in on my Ninja Grip system. No way is it related to the pin 4 mod, no way, it's just a standard bad connection. The solid screen means the program isn't starting up, and the lockout has no effect on what the CPU is doing, outside of resetting it.

Thanks for the assistance, I appreciate you taking the time. I don't want to potentially derail this thread any further so this will be my last post.

As I said in my first post, many games boot perfectly the first time on the modded NES. Metroid, Maniac Mansion, and many others come up like magic first try. The motherboard connectors have been cleaned as part of the modding process. The 72 pin connector is new. Most games "just work". KA and others, "just do not work". All the games that "just do not work" work fine in my stock NES.

I believe your knowledge is much greater than mine when it comes to the NES, and I agree that 99% of the time the solution is cleaning. I also believe you that the grey screen means the game isn't loading, and I believe you when you say it should have nothing to do with the security lockout chip. However, basic troubleshooting skills tell me that if a game works 100% of the time in a stock system (and has been cleaned etc etc) then the problem isn't the game. Also they tell me that if many games boot up 100% of the time in the modded system, the system itself is at least basically functional. So what that tells me is that the first place to look is the differences between the two systems... the obvious answer is that one system has pin#4 on the CIC cut and the other doesn't. It might not be the culprit, but it's still the first thing to investigate/eliminate.

You are probably right, the CIC mod probably has nothing to do with this. I'll stop posting now.

depends because the leg is snapped off "floating" on the CIC but it has a pull-down on the chips die

if it randomly stops and starts working and the power power light/led is turned solid off when the system is on and (doesn't blink) that means the system is locking out in key mode

otherwise no you're good to go buddy! we don't know how many consoles are effected by this probably never will..

you don't need a game inside the slot to test this

EDIT: if the die has a "pull-up" it would be in lock mode .. i guess it's a "pull-down" or floating wouldnt work... all the bits in the 10nes ROM dump were inverted so i'll say pull-down.. misinformation is bad

3kyousuke wrote:You are probably right, the CIC mod probably has nothing to do with this. I'll stop posting now.

this is what the thread is about feel free to post

jims cool wrote:depends because the leg is snapped off "floating" on the CIC but it has a pull-down on the chips die

if it randomly stops and starts working and the power power light/led is turned solid off when the system is on and (doesn't blink) that means the system is locking out in key mode

otherwise no you're good to go buddy! we don't know how many consoles are effected by this probably never will..

you don't need a game inside the slot to test this

EDIT: if the die has a "pull-up" it would be in lock mode .. i guess it's a "pull-down" or floating wouldnt work... all the bits in the 10nes ROM dump were inverted so i'll say pull-down.. misinformation is bad

3kyousuke wrote:You are probably right, the CIC mod probably has nothing to do with this. I'll stop posting now.

this is what the thread is about feel free to post

Yep, you're right, everything is behaving as expected in a system with pin#4 cut... powering on w/o a cart in is a grey screen, reset button doesn't work (I think that's to be expected, if not, I've got something else going on wrong). Thanks a bunch for the additional information.

To vindicate what 3gengames was saying, I FINALLY got KA to boot on the modded system, but get this: It only boots if the game is barely in the 72 pin connector, and is left in the upright position. In any other position, it just won't boot. Pop it back into my stock NES and boots up first try... *shakes head*. Considering that the pins on the motherboard are clean, does this mean I probably got a defective new connector?

I also wanted to say thanks to both you and 3gengames, lots of forums are not as friendly (or are downright hostile) to new people (especially ones who can be stubborn like me). You both have been awesome.

Edited to add: I could probably swap the new connector onto my stock NES and see how it behaves...

kyousuke wrote:Yep, you're right, everything is behaving as expected in a system with pin#4 cut... powering on w/o a cart in is a grey screen, reset button doesn't work (I think that's to be expected, if not, I've got something else going on wrong). Thanks a bunch for the additional information.

reset button should work.. i believe your chip may be damaged.. i've seen that happen to people
heres a diagram of how you can fix it.. i posted a photo of a patched board in this thread already



if you're not planing on using a copynes for running code or dumping the 2.2uf capacitor in the side photos can be recycled (instead of the 10uf).. the diodes don't need to be removed unless you have super rare third party games.. protects their little -5v zapper circuits

what does the chip say on it?

EDIT: if your reset button doesn't work (power light turns off when the button is pushed) it's not likely the connector.. and if you're not very good at clipping pins i could add an alternative that requires one less jumper and only one pin 1 of the inverter chip to be lifted and the circuit would still be electronically correct.. just not "perfect" wouldn't hurt anything still.. if you would rather that i will need some time... finishing up the JCIC and times short =)

EDIT2: you need the reset button for some good games that have battery backed ram or you'll loose your save data... also noticed in the instructions i left out that pin 4 of the inverter should be lifted it's an output that goes to the keys clock pin.. not a big deal though because it would output ground so i don't think anything would care.. should also note the little green jumper in the wiring diagrams explained in the schematic

kyousuke wrote:powering on w/o a cart in is a grey screen, reset button doesn't work (I think that's to be expected, if not, I've got something else going on wrong).

That's definitely wrong.

To vindicate what 3gengames was saying, I FINALLY got KA to boot on the modded system, but get this: It only boots if the game is barely in the 72 pin connector, and is left in the upright position. In any other position, it just won't boot. Pop it back into my stock NES and boots up first try... *shakes head*. Considering that the pins on the motherboard is clean, does this mean I probably got a defective new connector?

It really sounds like you do have a defective (or at least misadjusted) one.

Edited to add: I could probably swap the new connector onto my stock NES and see how it behaves...

That would be a great plan.

I really don't think the CIC is what's wrong here. If you do go through with that plan, please read my suggestions here and here—it's a far easier modification than the one jims suggested.

the reset button should work if the CIC functions .. can't believe you said otherwise.. the cic is basically (more or less) the reset button.. did you read the whole thread? look at the pinout pin 7 is the reset button.. you already know that though because you circuit is 150% better right?

please for the love of god don't flood this thread i answered because I KNOW THAT I KNOW.. its a damaged CIC .. 100%

JCIC and Ciclone both can be clocked at 1hz though i haven't tested it with your circuit but it should be safe.. but that's not what this thread is about is it? we already have a bloody debate about it in the other thread i'm sure everyone has seen it

you don't need to defend yourself its alright i know you didn't read everything in the thread it's getting very long it happens .. i'm planing on updating the first post with symptoms of both damaged and locked cic's.. and all the other info for people

EDIT: check for +5 volts on pin 7 when you hit the reset button only way it's not the CIC

"kyousuke"? Sounds an awful lot like kyuusaku. Might want to consider changing your name to avoid confusion if you decide to keep on posting on this forum.