Multicarts not working on Famicom Classic HVC-001

[VegaVegas]

Hi there, I struggle with a problem I can't solve by now. I have a Famicom Classic console (the first version, not classic mini) that functions rather strange- all normal carts work just fine and the games work just as normal and you can play through them but all multicarts I have simply refuse to work. They freeze right on the selection menu or while the game starts. There is no exception, ALL multicarts I have just don't work at all

What I've done is change 74LS139 into a new one, replaced the voltage regulator for a new one and added a small capacitor to the PCB from another Famicom (originally I noticed some empty slot for a small cap so I added it) but there is absolutely no change whatsoever, the console behaves the same. I think there is some problem with M2 pin or clock in the console but can anyone guess what may be faulty here the most likely?? Maybe some small component should be replaced or changed or something??
http://nesdev.com/Ntd_8bit.jpg

The console model is HVC-001 and all multicarts are 100% working fine on all consoles and they are all made in 1990s, some of them are IC and some of them are glob top if that matters. Please for help and suggestions, many thanks in advance!!

[FAMICOM_87]

did you try old multicarts from late 80's with normal chips ?
original consoles sometime do not work with newer pirate multicarts with glop tops 

[VegaVegas]

OK, to be specific I don't know the exact manufacturing date of those carts, they are just old carts that were sold on markets back when we were young (the majority of us). They all work fine on all other original Famicom and Famiclone consoles and there is only problem with them on this one specific original Famicom console, there must me something wrong with this unit but I can't figure out what

[FAMICOM_87]

very strange , did you try flash carts like powerpack and everdrive ? 
on my original famicoms one is from 1984 the other is from 1989 , not all multicarts work especially glob tops from late 90's and 2000's
even NES powerpack only work on my 1984 one.

[VegaVegas]

I don't have Everdrive N8 right now unfortunately. I heard that there are some Famicom motherboard revisions with minor changes, my Famicom is HVC-CPU-05 that causes problems with multicarts. Anyone have any idea how to fix it if possible??

[aitsu124]

Not sure. I only have one multicart, but it does work perfectly fine on my original FC. Is yours an older or newer original? You can tell this by whether or not it has the "FF" on the front red label. Mine's a newer one.

[VegaVegas]

From what I've read on the internet, it seems like this is one of the earliest Famicom revisions from 1983 and the clock that is generated in the console might have different electrical characteristics causing this, whether this is CPU or components that connect to the CPU I'm not sure but probably sounds a little more serious. Can any experts help in this?? The CPU might still be defective unfortunately, so far I've tested a bunch of older revisions of Famicoms (without the FF on the front decal) and the multicarts work perfectly fine on others
Post Merge: February 08, 2018, 10:29:18 am
OK, it looks like I've found solution to my own problem (probably)- it looks like the CPU is probably defective. I have no idea whether these older CPUs are worse or my unit was just broken. The part number is RP2A03. I did a test where I swapped CPUs between this faulty Famicom Classic and working Famicom AV. Once I tested Famicom AV with the iffy CPU, multicarts didn't work and normal games worked even worse, overall the console behaves strangely but when I tested Famicom Classic with Famicom AV CPU, the console worked perfectly fine, even with all multicarts. So to everyone that has a Famicom Classic with the motherboard HVC-CPU-05 I suggest you should test if your board can play multicarts or flashcarts like Everdrive. Looks like the worst possible scenario unfortunately but at least I've found the issue, the only thing I can do here is swap the processor from another donor I think

[Nesmaniac]

I have one of the oldest famicoms out there (newest chip in it is 27th week of 83) and CPU 1983 no revision. Board little 3 revision number beside p1 controller port on both sides. Upon trying Mario 3 the graphics was all messed up and radio station interference big time. The bottom board had 2 ceramic caps and 1000 ohm worth of resistors soldered on bottom of board which I removed before realizing nintendo had installed them. Once removed I could get nothing but light grey, blue, and occasional purple screen. Figuring it might be RF related I decided to do Da Bears AV Mod by desoldering RF components and routing the composite video through the disabled RF port. Still same results so I knew the bottom pieces needed to go back. I could not find exact board I have but found a earlier version with same resistors and caps so I put those where pictured and it worked fine. I've not tried any multicarts as of yet on this one but have tried them in other square buttons without issue (150 in 1 from aliexpress the $5.50 one) but I'm getting it restored now that it's working & made it accept NES controllers last night so I will have it buttoned up soon and let you know if it works with the multicart & if so you might want to try the caps and resistors on the bottom of the board. Don't trash that CPU it's probably fine the early systems just seemed to have some bugs that was apparently easily remedied on the bottom of the board with a few components. I was amazed actually that I got this one going because at first seemed no hope. It's a smooth flap dust cover too, only one I've been able to find after searching through 100's of famicoms.

[FAMICOM_87]

I've not tried any multicarts as of yet on this one but have tried them in other square buttons without issue (150 in 1 from aliexpress the $5.50 one)

150 in 1 is new and it has not only glop top chips inside  and it is designed to work on NOACs and original hardware, so  you have to try older multicarts with only glop tops (late 90's and 2000's, but not very old ones from late 80's and early 90's with normal ICs they usually work fine with original hardvare and even with NOACs .

[Nesmaniac]

I've not tried any multicarts as of yet on this one but have tried them in other square buttons without issue (150 in 1 from aliexpress the $5.50 one)

150 in 1 is new and it has not only glop top chips inside  and it is designed to work on NOACs and original hardware, so  you have to try older multicarts with only glop tops (late 90's and 2000's, but not very old ones from late 80's and early 90's with normal ICs they usually work fine with original hardvare and even with NOACs .

I tried the new 150 in 1 today and it don't work in my very early system H1096000 and not only did it not work but neither did older pacman clone cart that came with a micro genius console I bought but I expected that since I had tried those games in another famicom I had with no success. I'm happy this cart I got in today from Japan for $220 works along with every other authentic famicom cart I've tried so far. Bull charge destroyed me.

https://scontent.flex1-1.fna.fbcdn.net/v/t1.0-9/27858064_1923559364353060_8296449666632720235_n.jpg?oh=d0b27b197796834eb3eb147ace6a0d91&oe=5B15CE02

https://scontent.flex1-1.fna.fbcdn.net/v/t1.0-9/27973383_1923562471019416_4712404396302089549_n.jpg?oh=93f6cb1a89f079c5d804a35a11ac4c42&oe=5ADB6164