Nes (72-pin) to Famicom (60-pin) converter mod

[GadgetUK]

That's great news!  Fascinating your cart needed grounding in 3 places, very odd.  I would have expected ground to be ground, unless one of your vias is introducing resistance or something - maybe a bad via?  In any case this makes 4 counts of it solving all the problems now!  Thanks for doing the mod, and for sharing your experiences related to grounding on the AV Famicom.

[GadgetUK]

Great! ordered some right now. Will check it out once it gets here and let you know if everything works.
Again, thank you for researching it and finding a solution, once i see how it works for me i will update the guide.

How did you get on?  I was hoping to hear positive new and that would make 6 out of 6 where it fixed the issues!   I really wish someone would test this on an Analogue NT, because I believe the same issue is affecting that system with the ED too.  I did consider buying one but they seem to be around the $500 plus mark which is insane imo.

[Barawer]

Great! ordered some right now. Will check it out once it gets here and let you know if everything works.
Again, thank you for researching it and finding a solution, once i see how it works for me i will update the guide.

How did you get on?  I was hoping to hear positive new and that would make 6 out of 6 where it fixed the issues!   I really wish someone would test this on an Analogue NT, because I believe the same issue is affecting that system with the ED too.  I did consider buying one but they seem to be around the $500 plus mark which is insane imo.

Did not receive the copper tape yet. As soon as it arrives I will comment here, and i will fix the guide. I'm sure it will work since we have enough evidence to support it

[Barawer]

It's working! Great Great job GadgetUK, i will update the guide soon with some pictures. I did a pretty bad job with fitting and taping the copper tape, so if anyone has some better work i would like to use their pictures if you can.

[GadgetUK]

It's working! Great Great job GadgetUK, i will update the guide soon with some pictures. I did a pretty bad job with fitting and taping the copper tape, so if anyone has some better work i would like to use their pictures if you can.

Awesome!!! That's 7 out of 7 where this has worked, so it's safe to say it is a fix for these adapters.  I think the same fix will work when trying to use an N8 on the Playchoice 10 (I've contacted a chap on YT and he's going to try it), and I believe the same problem is happening with the Analogue NT and N8 - but in that case I suspect the shielding wants to go over the NT main board cart traces, and I don't know anyone with an NT that has the skills to attempt this fix (yet).

[Barawer]

Can someone please check Kirby's Adventure (U) (PRG1) [!] for me? when i run it with the mod it works fine until stage 1 level 4, and gets stuck in the middle there. in my nes it works fine

[GadgetUK]

Will check it out but pretty sure I got past that stage last week!  Have you made sure the copper is smoothed flat by wiping over it?  Also check cart and socket edges are clean.  I've still not had a single fault since doing the mod!  Don't forget, I also have a seperate wired m2 line via 100ohm resistor too.

[GadgetUK]

As well as making sure copper tape is rubbed flat, make sure there's nothing on the PCB underneath.  I had someone tell me it wasn't working 100% - he had placed insulation tape on the PCB first, with copper tape on top of that - that won't work, the copper tape has to be as close to the traces and vias as possible.  Also check ground is good, and contacts on both edges of adapter are clean, and famicom slot is clean.  Slightly dirty ground connection won't help.  I also suspect that having severed m2 line at both ends, and replacing with a wire in series with 100ohm resistor helps, because then the m2 clock cannot interfere with nearby traces

[thecavalry]

Still no issues here on my end to report. I didn't bother cutting the m2 trace. I just have the tape on the front(?) side, grounded, and wires for mmc5 and expansion audio resistors on the back.

[Barawer]

Thanks, i will try to put the copper tape again. maybe i'll give it to someone who knows how to make sure its flat

[GadgetUK]

Rub over the tape with a rag or something! All the ripples and bubbles vanish and it's then totally flat!

[Barawer]

Allright! I removed the old tape and put some new one. Kirby works great now!
One thing that i noticed is with the old tape, the N8's self diagnosticte test gave chr: error 03 (on the NES itself it was fine) and now all tests are OK. maybe i did something wrong there.
Oh well, it works!

[GadgetUK]

Allright! I removed the old tape and put some new one. Kirby works great now!
One thing that i noticed is with the old tape, the N8's self diagnosticte test gave chr: error 03 (on the NES itself it was fine) and now all tests are OK. maybe i did something wrong there.
Oh well, it works!

Great stuff!  Very interesting you got that error 03 - When I get another unmodified adapter I will test the diagnostics to see what it reports.  I've not had a single problem since doing the mod.   We just need someone to try the same copper tape fix on the Analogue NT motherboard cart traces now because I suspect that could solve the similar glithes that system has with the N8.

[Bluesteel]

Hi I tested the pins and found that you can't go off of the printed "1" that is on the pcb. Pin one for the nes side is actually on the right and not the left. The "1" for the fami side is correct.

So in your picture of the adapter with the copper shield you are actually connected to pin 36 which is 5v. I would use the spot just to the right of that where you cut and folded the copper. That runs to pin 72 and is also ground.

I used a pin out guide and then checked every pin connection to verify how it's wired.
Link:
http://nesdev.com/NES_ADAPTER.txt

More info:
I have a nes everdrive and a Av famicom 2nd gen. The unmodded adapter would work for real carts but with the n8 I got errors and random characters appearing in the n8 menu. Lots of glitches and crashes.

this mod hasn't fixed mine yet, I'm awaiting some components before I try again. I was using 2watt resistors and ordered some 1/4 watt. I use metallic film. Also my shield is connected to 72, initially it was on 36 like you're picture.

[Barawer]

Hi I tested the pins and found that you can't go off of the printed "1" that is on the pcb. Pin one for the nes side is actually on the right and not the left. The "1" for the fami side is correct.

So in your picture of the adapter with the copper shield you are actually connected to pin 36 which is 5v. I would use the spot just to the right of that where you cut and folded the copper. That runs to pin 72 and is also ground.

I used a pin out guide and then checked every pin connection to verify how it's wired.
Link:
http://nesdev.com/NES_ADAPTER.txt

More info:
I have a nes everdrive and a Av famicom 2nd gen. The unmodded adapter would work for real carts but with the n8 I got errors and random characters appearing in the n8 menu. Lots of glitches and crashes.

this mod hasn't fixed mine yet, I'm awaiting some components before I try again. I was using 2watt resistors and ordered some 1/4 watt. I use metallic film. Also my shield is connected to 72, initially it was on 36 like you're picture.

Hi, can you please upload pictures of your board? i used the same pinout to verify when i did my mod. maybe something is different on yours, i want to compare it to mine.