Famicom Reliability

[Great Hierophant]

From all that I have read, I get the following impressions of the general reliability of Famicoms :

Square buttoned Famicoms are strictly museum pieces.

HVC Famicoms are not particularly reliable and suffer from questionable PCB build quality.

GPM Famicoms and Twin Famicoms have tolerable reliability, equivalent to a NES Front Loader.  If treated well, they can be OK.

AV Famicoms and Titlers will work well unless they have been abused and look far superior to a similarly-reliable NES Top Loader.

Is this a fair summary of the general reputation of these models?

[P]

Square buttoned Famicoms are strictly museum pieces.

At least the controllers. There may be nothing wrong with the Famicom main units as square button controllers was used all the way to board version hvc-cpu-05 or something I think (apparently at least to 06). Most had been replaced by round button controllers though which I guess is why square buttons are rare.

HVC Famicoms are not particularly reliable and suffer from questionable PCB build quality.

Who says that? I'm using an HVC model and I don't have more problems than I have with any other old console. They might have earlier versions of the CPU and PPU that doesn't support all the features of newer revisions, but I never heard of any incompatible games (wouldn't be surprised if there are though). The earliest HVC models (at least earlier than hvc-cpu-05) however may be faulty and was taken back by Nintendo which is why they are so rare today.

GPM Famicoms and Twin Famicoms have tolerable reliability, equivalent to a NES Front Loader.  If treated well, they can be OK.

Well I think later HVC models are also equivalent to a NES front loader (if you AV-mod it). There are advantages and disadvantages with both.

AV Famicoms and Titlers will work well unless they have been abused and look far superior to a similarly-reliable NES Top Loader.

AV Famicoms are the most popular mostly because they have AV-output and NES controller ports. But they have their disadvantages as well (no mic).

[zmaster18]

All I know is that earlier Famicoms handle the Noise channel a little differently:


https://www.youtube.com/watch?v=avNLbQVKHIc

[number47]

tolerable reliability, equivalent to a NES Front Loader.  If treated well, they can be OK.

Can't agree with that - front loader has very lousy cartridge loading "contraption". The pins are also a pain to clean and mend.

[Great Hierophant]

Once you find a way to deal with the front loader's connector, which today may be a simple $20 Blinking Light Win kit, then it is as reliable as any other Nintendo machine.  My front loader's connector is original and is very reliable.  

As far as CPUs go, the RP2A03 without a letter suffix lacks the looped noise feature for that APU channel.  This causes the lack of "electrical noise" in Fire Man's stage in MM1 and Quick Man's stage in MM2.  The RP2A03E, RP2A03G and RP2A03H all have the looped noise feature and certainly will be found in any Nintendo console manufactured in 1985 to 2003.  I do not believe that the electrical noise in these games is unintentional because the noise fits the music so well.  I have seen a HVC-CPU-06 board with a 2A03 and another HVC-CPU-06 board with a 2A03E, so the addition was probably made within the first eighteen months of the Famicom's production.  

However, I cannot say the same about the Balloon Fight sample.  Apparently Balloon Fight was released for the arcade in a Vs. Dualsystem cabinet in 1984.  The Vs. System appeared to use RP2A03s without suffixes.  The game was released for the Famicom on January 21, 1985 and is a cut down version of the arcade version.  There is no harsh noise at the end of the game over screen as the Vs. Balloon Fight is emulated in MAME, so that may be how it should sound.

[P]

I read it's CPU revision E and earlier that lacks looped noise but that could have been an old document. Rockman came out in 87 so yeah the electric noise could be intentional.

The RP2A03E, RP2A03G and RP2A03H all have the looped noise feature and certainly will be found in any Nintendo console manufactured in 1985 to 2003.

The 06 in that video has 1984 written on it though and seems to lack looped sound. And it seems to have square buttons.

[Great Hierophant]

Looped noise works fine in an RP2A03E : http://forums.nesdev.com/viewtopic.php?f=9&t=4279&hilit=2A03E#p35831

Regarding the PPU, there is a register ($2004) that was write only in earlier revisions that became readable by the 2C02G-0.  One game that reads this register is Micro Machines, so its menu screens may appear slightly glitchy on an earlier Famicom.  I have seen or read of RP2C02A, RP2C02B, RP2C02C, RP2C02D, RP2C02D-0, RP2C02E-0,RP2C02G-0, RP2C02H-0 PPUs.

[P]

I see, interesting that the only game found to read $2004 is unlicensed. Maybe licensed games intentionally didn't read it as to keep compatibility with earlier Famicoms. But if that is the case I wonder why it was made readable at all.

This is the document I was talking about http://nesdev.com/NESSOUND.txt (last paragraph "RP2A03E quirk") but I guess it must be wrong if Kevtris is right.

Yeah since the VS System Balloon Fight game was first it's fair to guess the looped noise part is unintentional on that game. So there are games that "needs" the earlier CPUs to sound "as intended" and other games that needs later CPUs.

[fredJ]

The problem with the earliest model consoles is that they often die.
They can be repaired, but still.

Out of the earliest model HVC I have, 75% are broken.

Out of later model HVC and GPM I can't say which is more reliable. It depends on how much they have been used.
The GPM model was designed in 1989 and the SFC was released in 1990, so clearly the 1989 console would not get the same amount of abuse as a console from 1985.

If a console looks nice, it is more likely to work, that's my tip.
Famicoms also seem to degrade with age or use, causing disturbances such as buzzing sound and increasing jailbars.

Earlier model HVC have a simpler power board too (if I understand correctly) and the design is just more prone to fail. Later models have a fuse which is always nice.

Twin famicoms usually work but can also degrade and show jailbars. Their caps sometimes dry out, and their power board can be flawed. There are different versions of the power board, probably because the earlier models are more likely to fail.
Well, twins usually work, but I would say that 1-2 out of 10 have some major problem that requires error searching (more than replacing a cap).

AV Famicoms work in 90% out of cases, but if you find something in a junk bin for 100 yen that looks like crap, chance is higher it doesn't work. I don't know what breaks them, it would be interesting to know. Maybe if it is stored in a moist basement for 10 years or so.

[chowder]

Considering their age, I've found the HVC Famicoms to be pretty reliable.  Capacitors are never going to last for that long so will need to be replaced in some cases, blown power regulator (7805) seems to be a common issue, but that could be more down to people using incorrect power supplies than unreliability as such.

Famicoms are pretty simple and easily repairable in general, but consoles are classed as toys by most and hence subject to the usual abuse - liquid ingress, connector pins being bent by kids ramming random objects in there etc, etc.

[fcgamer]

Looped noise works fine in an RP2A03E : http://forums.nesdev.com/viewtopic.php?f=9&t=4279&hilit=2A03E#p35831

Regarding the PPU, there is a register ($2004) that was write only in earlier revisions that became readable by the 2C02G-0.  One game that reads this register is Micro Machines, so its menu screens may appear slightly glitchy on an earlier Famicom.  I have seen or read of RP2C02A, RP2C02B, RP2C02C, RP2C02D, RP2C02D-0, RP2C02E-0,RP2C02G-0, RP2C02H-0 PPUs.

What about the other Codemasters games, do they read this as well?  The reason I ask is because most, if not all, of my official BIC Codemasters Famicom carts display some minor glitches when ran on my Twin Famicom, mainly just at the title screen.  I don't remember if I had this problem when running them on a clone or not, and none of my clones are hooked up at the moment to test.

[P]

I'm curious what PPU version that Twin has. I understand if you don't want to go through the trouble just to check that though.

[fcgamer]

I'm curious what PPU version that Twin has. I understand if you don't want to go through the trouble just to check that though.

I'm not a techie guy at all, so I have no idea what I would even be checking     

[Great Hierophant]

I'm curious what PPU version that Twin has. I understand if you don't want to go through the trouble just to check that though.

I have seen pictures with an RP2A03E and a RP2C02E-0.  I would suggest that there are Twin Famicoms with RP2A03G and RP2C02G-0 as well, (the Turbo variant most likely) considering how common the latter chips are. 

[P]

So in short it's possible the other Codemaster games do read $2004.

I'm curious what PPU version that Twin has. I understand if you don't want to go through the trouble just to check that though.

I'm not a techie guy at all, so I have no idea what I would even be checking     

Just check the label on the CPU (RP2A03) and PPU (RP2C02). If there are any characters after the name, that is the revision number. For example PPU version G should be labelled "RP2C02G", and if there is no letter at all it's the original unrevised PPU (of course not happening in the case of a Twin).

Don't ask me why electronic companies loves unpronounceable names with lots of numbers.