Centipede - General Mainenance and Overview?

I forgot to answer back. here is a peeling cap. I would surmise it's from excess heat exposure. which of course will result in it drying out.

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also these original 10 uf 160V caps almost always leak on G07s

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"Pealing down" refers to the plastic outer cover. As the capacitor starts to bulge, the plastic (which normally laps over the top of the cap) slides down. This happens just before the cap either relieves through the bottom or turns into a mini-rocket and shoots to the top of the cabinet.

Modern caps have score lines in the top to prevent them from blowing off the board. The top just splits and relieves the pressure.

I was experimenting in the mid 1970's with a Radio Shack kit. I was installing different components in a neon lamp circuit. I put 120 volts to the circuit when I had an underrated capacitor installed.

I heard "REEEEEEEEEEEEEE - BANG" and had that cap top hit the ceiling in my bedroom.

Fortunately, my parents weren't home to hear THAT.

I'd suggest a fiberglass pen cleaning of the edge connectors regardless of whether the connector is burned or not. The edge connectors are tin coated, which corrodes slightly resistive. This drops the voltage to the board, and makes the game twitchy or inoperative.
 
@andrewb I've posted some pictures here -How do I remove the 2N3055 from the pcb? Do I just need to take the two nuts off the component side or would I need to unscrew one side and de-solder the other side on the solder side?

Also, I don't see a +5v test lug on the board, only-5, GND, +12, and others, but not a +5. Am I missing something? I believe the attached photo of the pot is what I would need to adjust if required, although it looks to be glued - is that normal and just may need to cut the glue if I need to adjust?
To remove the 2N3055 you remove the nuts and then desolder the two small pins in your second picture. You don't need to desolder the screws on the bottom.

For the +5V test point, if there isn't one on the board then you can measure from the positive lead on C1. The glue on those adjustment pots isn't really locking them down, just helps stop a light bump from shifting it. Should be easy to turn with a screwdriver

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To remove the 2N3055 you remove the nuts and then desolder the two small pins in your second picture. You don't need to desolder the screws on the bottom.

For the +5V test point, if there isn't one on the board then you can measure from the positive lead on C1. The glue on those adjustment pots isn't really locking them down, just helps stop a light bump from shifting it. Should be easy to turn with a screwdriver

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Got it - thanks. I just wanted to be sure to test the +5 with the edge connector removed to be sure all was well!
 
You don't want to remove the solder on those screws.

Undo the nuts on the parts side. Then remove the solder from the two pins. NOTE: It's important to use high heat here, as you need to get ALL of the solder out of those holes. Otherwise the part won't let go. Look into the holes after you suck the solder out. If there is any silver inside the holes, re-apply fresh solder, and try again.

Once you have it all out, the part is sometimes still stuck to the heatsink. I take a pair of needlenose pliers (ones with rough jaws, not smooth ones), and *gently* grab the top of the 2N3055, then rock it back and forth to crack it free. Do not jam a screwdriver under it to pry it up. If it doesn't crack free with only a little help, then there is still solder in the holes, go back and re-apply solder and try again.

And yes, there is no 5V test point. But as was said above, use the positive (+) side of the C1 cap. The whole fat trace that is connected to is 5V.

And yes, you will need to remove the silicone dab from the pot in order to adjust it. That's fine. Put some DeOxit in that pot too, if you can. I just replace the whole pot with a 3386-style cermet pot. 1k ohm. But that's optional. If the pot isn't mangled, the original will be fine.
 
@ArcadeTechGW @andrewb @Texas_Funnyhair @mecha
@Yoeddy
@CharlieG

I got back to this today. I did replace the 2N3055, sprayed connections with de-oxit, cleaned the pcb edge with a fiberglass pen, and recapped the monitor. I found that the chassis had been replaced with an EAGO 53210, which I capped and reflowed. I adjusted the power supply to 5.010v DC at the test lug on the pcb.

Everything powered on, and the monitor needs adjusted, but I have a column containing the letters I and M to the right side of the screen. Any suggestions on where to go from here? Sorry for the bad photos, tbis was in my garage with overhead lights, but you can see the letters I'm referring to.
 

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I agree with Mecha. Flip the test switch and turn the game on. You'll probably hear some beeps. Seems like a memory problem.
 
I think on Centipede it's on the coin door. I've noted in the past I've been in so many Atari games I don't know where they're all located lol
 
I agree with Mecha. Flip the test switch and turn the game on. You'll probably hear some beeps. Seems like a memory problem.

I think on Centipede it's on the coin door. I've noted in the past I've been in so many Atari games I don't know where they're all located lol


Yep..on the coin door. 9 beeps, so looks like a RAM chip is bad. Do I just need to desolder the bad chip and solder a new one in?
 
Yes. Then you cross your fingers that you installed the chip cleanly and there aren't other issues. 😄
… I should have mentioned that some folks like to use sockets for ram. Makes it easier on the next person who has to replace that chip. Others say it's a failure point. Make your own decision.
 
Thanks guys. I'll get the chip and a socket. Looks like some of these caps could be replaced as well. Thoughts?
 

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No.

Caps on Atari boards are mostly Nichicons, which are very good quality. And they don't work that hard. So they are always fine, unless they've been physically stepped on or torn off. Keep them original. Replacing caps is not always 'upgrading' a board. Only replace caps when you can measure that they are bad, and in monitors (where they are hotter, and run at higher voltages, so those do go bad).

That is just gunk on that cap. (Notice the same gunk on the dipswitches next to it.) Wash that board in a sink with some Krud Kutter, a soft paintbrush, then rinse with hot water. Then stick it in front of a fan overnight to dry. It'll look better than new.
 
I recently picked up a centipede as well. I feel like this thread will be quite helpful once I get around to working on it. Thanks for all the useful info!
 
Centipede is one of the most popular games. You've got a TON of resources to help figure out anything that might be wrong.

Good luck.
 
Atari used very good quality caps. And you see the difference after 40+ years. Also, the caps on the game board and AR generally don't do a lot of work. They are mostly larger caps used for filtering, are low voltage, and aren't exposed to high temperatures (which are the 3 things that cause caps to age faster. Small, higher-voltage, and higher-temp caps are the ones that tend to actually go bad.) As a result, these caps are all still fine. Replacing them won't fix any problems or make your game work any better. You're just making the board less original by replacing them.
Originality of A/R boards doesn't seem to be a concern. If you're replacing the 2N3055 cap, there goes the originality w/o touching anything else.
Big blues generally either work or they don't. And you can measure exactly how healthy any big blue is with a simple voltage measurement. They don't go bad super often, but when they do, it's usually during the first power-up after the cap has been sitting for years unpowered. And the game usually just won't boot.
Not necessarily. I bought a Centipede cabaret in May of 2008 that ran fine for a month. Suddenly, the game started taking a minute to power up. After asking around, a collector friend who was big into Atari games told me what the problem was, and told me to replace the Big Blue cap ASAP. After ordering a new one, I replaced the original cap and I was back in business!
 
Not necessarily. I bought a Centipede cabaret in May of 2008 that ran fine for a month. Suddenly, the game started taking a minute to power up. After asking around, a collector friend who was big into Atari games told me what the problem was, and told me to replace the Big Blue cap ASAP. After ordering a new one, I replaced the original cap and I was back in business!
It sometimes seems like it, but this is not black magic. If you tested that big blue after you started experiencing issues, you would have found it to be out of spec if that was really the issue. Things go bad over time and sometimes a component finally gives up though it was OK a month before.

Certainly, if you tested that big blue now with the right equipment, you'd be able to determine if it is in-spec.
 
Originality of A/R boards doesn't seem to be a concern. If you're replacing the 2N3055 cap, there goes the originality w/o touching anything else.


If you found a pristine barn-find 1966 Mustang in all-original condition, what things would you replace on it? Just the tires, hoses, and anything else critical, that is needed to get it running reliably? Or would you rip out the interior and strip the paint too?

The goal of preservation is preservation. Replace as little as possible, and only what really needs to be replaced. Otherwise, preserve everything else for the long term. There's no need to hack a board up and replace all of the caps, when it's not going to improve anything.

Some people today might not care how original their boards are. But you have to assume that these games will go the same route as EVERY other vintage collectible out there. Cars, musical instruments, art, hi-fi gear, tube amps, furniture, clothing, coins, comic books, etc.

In EVERY other vintage/antique collectible hobby out there, the less work or modification a thing has had done to it, the more it retains its value over the long run. (And specimens that have had less modification/wear/restoration done to them are the ones that command the highest prices.)

The key is not to look at these games for what they are today. As preservationists, look at them through the eyes of a collector 20/50/100 years from now, the way we look at stuff that is 100 years old today.


Not necessarily. I bought a Centipede cabaret in May of 2008 that ran fine for a month. Suddenly, the game started taking a minute to power up. After asking around, a collector friend who was big into Atari games told me what the problem was, and told me to replace the Big Blue cap ASAP. After ordering a new one, I replaced the original cap and I was back in business!

As Kazoo said, you should have measured it either way. You don't have to guess how healthy a big blue is. You can measure it in ten seconds with a DMM, and know if it's on its way out or not.
 
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