Robotron cartridge - suddenly stopped booting

[Leonard Smith]

Weird one for me.
Been on a Robotron 2084 kick as of late.  Played a game and did well, turned off the console, removed cart and played a few games of Centipede.

 

I turned off the console and swapped out controllers.  Re-inserted my Robotron cart for another round and upon pressing power all I get is random vertical bars of color on the screen.  No amount of cleaning, reinserting or wiggling make a difference.
I even pulled out my backup 7800 console and same issue.  Is this common with the early games or is it possible that my A/V modded console may have fried it somehow?

All other games boot and play fine, so this is really a mystery to me as I've never had a cart 'go bad'...especially this one since it has worked fine over the past few months.

This was a NOS game that I bought from Best Electronics, and it looks new and the connectors look flawless. 

Overall, not a huge deal as I'm sure I can acquire a replacement cheaply since it's usually included in cart bundles.  Just a tad concerning since I was playing Commando and Water Skiing the other day...don't want this to happen to my more valuable carts.

 

[project7800]

 

I would pop the cart open and check it out. 

 

The above video is obviously for an 8-bit cart, but I could have sworn that I have seen a video of someone fixing a 7800 cart by doing the same thing. I just can't find it right now.  

 

[Leonard Smith]

I did open the cart.

There's a weird fix where the main rom chip has one of its legs lifted out of the through hole and a small resistor is soldered to it.  Looks like a very flimsy job, which is surprising considering this was a factory sealed copy.

Maybe the inserting of the cart jostled something.  Not sure.  First time I've ever had a cart stop working, and I've been gaming since the early 80's

[gambler172]

2 hours ago, Leonard Smith said:

I did open the cart.

There's a weird fix where the main rom chip has one of its legs lifted out of the through hole and a small resistor is soldered to it.  Looks like a very flimsy job, which is surprising considering this was a factory sealed copy.

Maybe the inserting of the cart jostled something.  Not sure.  First time I've ever had a cart stop working, and I've been gaming since the early 80's

you have a photo?

[Leonard Smith]

44 minutes ago, gambler172 said:

you have a photo?

 

[Trebor]

19 minutes ago, Leonard Smith said:

 

Atari CO24926 Rev B with resistor, maybe Rev C.

[Leonard Smith]

Interesting.  I'm newer to the 7800 so I was not aware of these fixes.

Would removing the resistor (or perhaps a bad solder joint) result in the game not booting at all?

At the end of the day, it's not a huge deal as I'm sure I'll come across extra copies of Robotron as I fill in gaps in my collections.  

[Trebor]

Considering the board has a 'deglitching capacitor' and the average life span of a capacitor is ~20 years, we are near double the average lifespan at this juncture.  Concern about that piece going bad and the board now not working at all may be a possibility. 

 

Though the resistor going bad is not outside of the realm of possibilities, it tends to last for a much greater period of time.

 

Nonetheless, removing the resistor I would think could (would?) leave the board/chip opened to being fried.  Though a better answer may come from one of our more seasoned hardware experts.

[alex_79]

Looks like one leg of that resistor is broken off to me, which leaves pin 28 (+5V) of the rom chip disconnected.

[Leonard Smith]

So maybe it got jostled loose and subsequently fried itself when I booted it up again.

Oh well.

[JonnyBritish]

Sorry your having Robotron issues as its one of the best 7800 games. still have yet to cross the 1 million point barrier. but got a dual edladdin controller just to play robotron

 

Also good to see you getting into Water Ski - Its a fun game bearing in mind its operating two characters using the joystick and buttons. Wonder if it could be hacked for two joysticks?

[Leonard Smith]

Thanks! 
I agree with Robotron being great on the 7800 - there's something about the arcade conversions on the 7800 that just feel right.  Totally dialed in for joystick control and just a total joy to play.  

Water Ski is growing on me.  It's like learning to do 2 things at once, but once you get the hang of the independent boat/skier control it starts to click.  Great risk/reward dynamic!

[Atariboy]

Ceramic capacitors are long lived components. I doubt it's bad.

 

While I'm sure someone somewhere does this, you don't typically see people replacing those when recapping things like consoles and computers from that era. It's the electrolytic capacitors that you'll typically see getting replaced when recapping something with both styles present like a Commodore 64 (I don't recall any ceramic capacitors inside my pair of Atari 7800's).

 

Like alex_79 says, it looks like a resistor leg broke off and needs to be replaced. 

 

 

 

 

Edited July 16, 2022 by Atariboy

[+-^CrossBow^-]

Where is the other leg of that resistor? It also looks like the leg it is attached to has been clipped so it isn't actually connected to the PCB.

 

[+Mitch]

It looks like the resistor is snapped off. If you replace it, that could fix it.

 

Mitch

[Leonard Smith]

53 minutes ago, -^CrossBow^- said:

Where is the other leg of that resistor? It also looks like the leg it is attached to has been clipped so it isn't actually connected to the PCB.

 

I don't know.
THat's how it popped out of the cart when I opened it.

One resistor end of the resistor wire is attached to the chip leg, and I don't see a second wire on the resistor.