Faulty Game Carts (and their possible causes)

[Jstick]

I recently aquired some cheap lots of VCS cartridges on ebay. After cleaning and testing, I discovered a few faulty carts. The games were functional, but exhibited some graphical anomalies.

 

Here is Moon Patrol:

 

 

Notice the corruption on the second ‘o’, as well as the overwriting of the Atari copyright with portions of the ‘Moon’ lettering above.

 

Also, Asteroids:

 

 

Notice the strange line patterning in the centre of each asteroid.

 

I’ve tested these carts on multiple systems with the same results. Also, I have duplicates of these titles from my personal collection that work just fine on the same systems.

 

Having never had one of my own personal carts fail, I’m wondering what might have happened to these? Water damage? Extreme temperatures? Static? Metal whiskering? Data rot? Factory defect in the mask ROM? It’s worth noting that the shells/labels themselves are in good condition, and the contacts appear normal after cleaning.

 

My understanding is that Atari cartridges are fairly robust (often being nothing more than a single chip on a simple PCB), but after seeing these functional but corrupted games I’m suddenly feeling a little paranoid about games in my collection with undetected errors...

 

 

[Keatah]

Any one of the causes you list could be the cause. Only way to tell is by a forensic-style exam. It could also be simple contamination inside the carts on the PCB traces, where a good cleaning and reflowing would fix that right up.

 

Unfortunately there's no indicator to say what the condition of the data in the cart is in. Or exactly what the contents are. It would need to dumped and bit-compared against a rom.

 

I see the possibility that consoles like the R77 could do a dump and display a checksum value which would be a nice test. Or better yet, md5.

Edited June 27, 2018 by Keatah

[Jstick]

I see the possibility that consoles like the R77 could do a dump and display a checksum value which would be a nice test. Or better yet, md5.

 

 

Great point, that would be an easy way to regularly test the integrity of one’s collection (sans exotic carts) during the course of normal play, and it would make good use of the fact it is already dumping the carts every time.

[+sixersfan105]

I have got nothing to add other than when I saw the title about faulty carts, before reading on, my bet was going to be on M Network games giving you trouble. I swear I have only been able to get 10% of M Network games working over the years. So poorly made!

[Jstick]

I have got nothing to add other than when I saw the title about faulty carts, before reading on, my bet was going to be on M Network games giving you trouble. I swear I have only been able to get 10% of M Network games working over the years. So poorly made!

 

 

Interesting... I have most of the M Network games and can’t say I’ve ever had an issue with any of them (aside from how awkward they are and not being able to stack them properly).

 

It’s the Activision carts that I personally find to be a bit touchy; the PCBs are a bit thinner than the Atari ones and tend not to make as good contact.

Edited June 29, 2018 by Jstick

[gorfcadet]

That is how my Asteroids looks on an HDTV. Looks fine on a crt. Not your cart or system; just how many lcds handle that game. Im guessing youre on an lcd anyway; if not, that is freaky.

[Jstick]

That is how my Asteroids looks on an HDTV. Looks fine on a crt. Not your cart or system; just how many lcds handle that game. Im guessing youre on an lcd anyway; if not, that is freaky.

 

 

Hmm, that can’t be it though as I have 2 other copies of Asteroids that don’t have the issue on the same setup, and running the game off of the Harmony cart is fine as well. There is something about that one particular copy that is faulty.

[gorfcadet]

 

 

 

That is strange. I have two copies of Asteroids and they both do the same thing on my lcd. They look fine on a crt. Were there any revisions to Asteroids? Have you tried them on a crt?

 

 

[Jstick]

 

That is strange. I have two copies of Asteroids and they both do the same thing on my lcd. They look fine on a crt. Were there any revisions to Asteroids? Have you tried them on a crt?

 

 

If you look closely you can see that yours is a different issue. In your screenshots, everything has consistent lines straight through it, including the ship. This is most likely a deinterlacing issue with your TV set.

 

In my case, only the centres of the asteroids suffer from corruption, the outer portions are solid blocks of colour as they should be. Notice the numbers appear correctly as well, and although it’s not obvious from my shot, the ship is also solid as expected and has no lines.

[toiletunes]

Asteroids had at least one revision (one has a copyright screen, one doesn't), I wonder if there were any changes

[Jstick]

Asteroids had at least one revision (one has a copyright screen, one doesn't), I wonder if there were any changes

 

 

This is true, but I have tested copies of the same revision as the faulty cart (both hardware and Harmony ROM) that don’t exhibit the issue. See my recent post, I’m am almost 100% certain that this is a genuine fault with the cart in question.

[+-^CrossBow^-]

Was gonna say, asteroids on the FB2 looks pretty much like your shot of it does with only the centers being stripped due to interlacing issues. And I'm pretty sure like Gorfcadet, that all copies of Asteroids look very similar on my LCD as well. I really think it is just a deinterlacing issue. But as Keatah stated, the only real way to know would be to dump the rom contents and compare them. There really isn't much else on the PCB for those older games aside from the masked rom itself that could be at fault.

[Jstick]

I really think it is just a deinterlacing issue.

 

If this in reference to my issue (and not gorfcadets), I'm going to reiterate that 3 other copies of the same game running on the same system and TV don't have the issue at all. When only 1 of 4 copies of a game exhibits a problem, simple logic tells us that there must be an issue with that particular copy.

 

Beyond that, the lines look nothing like deinterlacing when in motion, as the patterns jump around in a chaotic manner and are non-uniform.

[+-^CrossBow^-]

Beyond that, the lines look nothing like deinterlacing when in motion, as the patterns jump around in a chaotic manner and are non-uniform.

Did you mention that part originally?

 

Have you a video of this in motion as I'm curious to see how this compares.

[Jstick]

Did you mention that part originally?

 

Have you a video of this in motion as I'm curious to see how this compares.

 

 

Nope, no video, in fact it took me about 2 weeks to work up the motivation just to take and post those photos above

[Video]

Weird. If it wasn't for testing other games, I would have said LCD issue, as my games will look like that on some lcd, from a range of works perfectly to not at all, most fall in the b/w to graphical issues range. My Atari now lives on a crt, best way to avoid issues.

 

Now moon patrol is suffering some sort of corruption (copyright title glitched) could be a dirty contact, or an actual rom problem. Mask roms are super reliable in my experience,so it likely had that issue day one. I would try cleaning it though, checking traces, etc just to make sure.

[Jstick]

Weird. If it wasn't for testing other games, I would have said LCD issue, as my games will look like that on some lcd, from a range of works perfectly to not at all, most fall in the b/w to graphical issues range. My Atari now lives on a crt, best way to avoid issues.

 

 

While I am indeed currently using an LCD, I have played upwards of 200 VCS games on it with nary an issue to be spotted (including 3 other copies of Asteroids as mentioned), so it works just fine for my purposes. It has only been since I purchased some mixed lots of unknown provenance that I have run into faulty cartridges.

 

I have never had a cartridge from my personal collection exhibit an issue that couldn’t be fixed with a q-tip and some isopropyl alcohol, but I’ve cleaned the heck out of these 2 problematic games to no avail. I suppose one day if I’m bored I may pop the cases open and do a basic investigation as you suggest. And if I ever get a Retron, dumping becomes a possibility.