Atari "Big Blue" capacitor

Steverd

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I just pulled the Blue Blue capacitor out of my Battlezone.
27,000mfd 15vdc

My multimeter reads it as OL one way and 000.0 ohms switching leads.
My Blue ESR meters reads .13
My Purple ESR meter just reads in circuit/Leaky (already pulled from the power supply)

Does it sounds like a dead capacitor? I was thinking it was except the reading from my Blue ESR meter.

Thoughts on this?
 
I do not test these caps out of the transformer ass'y.

With everything installed, connected and powered up (including the game PCB), I check the AC (yes, AC) voltage across the cap (one lead on each terminal of the cap, doesn't matter which is where). This will measure the "ripple voltage" present. Ultimately, where it matters is on the +5V line, so I actually measure it (the ripple voltage) there first. Ideally, it's zero (but never is). Usually a few tens of mV is good, and it may work fine even up to a couple hundred mV. But the bottom line is, if the big blue cap is bad, you'll have significant ripple on the 5V line.
 
My experience:
The bigger the cap, the more likely it is to still be good.
I've yet to see a bad Big Blue. Not saying it doesn't happen, it's just rare.

Most of the ESR testers can't handle the large capacity of the big blu except the Russian one by www.radiodevices.ru (http://www.radiodevices.ru/esr/esr4.htm) so I wouldn't trust those results. if you don't have that one use Daren's suggestion.
 
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My experience:
The bigger the cap, the more likely it is to still be good.
I've yet to see a bad Big Blue. Not saying it doesn't happen, it's just rare.

Most of the ESR testers can't handle the large capacity of the big blu excpect the Russian one by www.radiodevices.ru (http://www.radiodevices.ru/esr/esr4.htm) so I wouldn't trust those results so if you don't have that one use Daren's suggestion.



google translated link:

http://translate.google.com/translate?sl=auto&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.radiodevices.ru%2Fesr%2Fesr4.htm&act=url

I have the russian one. I did not know it was capable of testing big blue. I probably have a dozen old ones. I will have to check them.
 
yup, it goes up to 65000 uF which is a lot higher then the others...

And it's not just the big blue......ALL "big" caps that I have come across have measure out just fine up to now, even those in my 1971 Seeburg jukebox. This is also the reason why filter caps are usually not included in cap kits.
 
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I've had to replace a few big blue's over the years. Just recently I was working on a Tempest where the +5v was jumping around between 4.2v and 5.3v. Edge connector was good, AR2 was good, etc. Replaced big blue and the +5v was solid after that.

I just purchased an ESR meter but haven't had a chance to put the kit together yet. I'm keeping this big blue around to see what kind of reading I get on it.
 
I just got through fixing an upright Asteroids a few weeks ago. When I got it there was a loud hum coming through the speakers and the start buttons were solid red.

It turned out that big blue was bad--thereby letting a 120Hz harmonic to get fed through the audio amps and the game pcb. Replacing the capacitor eliminated the hum and made the game work perfectly.
 
I'm sure there are more than a few instances where the Big Blue has gone bad, but the incidence of failure on these is so minimal that I'd dare to say that replacing the Big Blue should be the LAST thing you try on a game repair.
 
If only the people who _do_ replace Big Blue's blindly would ALSO replace the PCB edge connector(s) blindly....

Don't agree completely. Garbage in=Garbage out, so I _do_ check them always (first). I tend to work from power brick to AR-II to PCB.

On power bricks the most suspected part is the fuse holder. If in bad condition replace. Transformers never seem to die. Haven't found bad diode bridges either, but still check them and also the Big Blue. It's only a couple of seconds to know it's OK (either using AC ripple measuring or ESR).

Then it's AR-board checking all caps with ESR tester, the smaller one's often need to be replaced. AR board failures are plenty in burnt resistors and the big bottle transistor and/or bad audio amps. Smaller caps are bad sometimes on the AR boards.

Then it's replacing the edge connector. No questions asked, it goes. After 30 years the mechanical tension is gone. It is also the cause for many AR boards to go bad.

Then check the PCB for bad caps with the ESR. If everything works, that's about it.
 
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Changed more than a few Big Blues on my end

Has been a good "fixer" in my experience.

Just my opinion.

Cheap, easy and quick way to start fixing an Atari "issue"

Rob
 
From what I understand Big Blue is one of the first things you look at when having game problems. Bob Roberts recommends that you replace it either way if it is the original one.

Question: I have an unused Big Blue that was slightly dented. Can I still use it or should I get another? How much of a dent might be considered a problem?

Darren Harris
Staten Island, New York.
 
Of course Bob recommends replacing them all (even the good one's) because he SELLS them...car sales men recommend replacing your car too...

And we are just some nitwits who know nothing and have no experience at all.....

Replacing an original Big Blue that measures out good with either a capable ESR meter or the ripple AC measurement is a waste of money and an unnecessary load of the environment because you throw away a perfectly good cap.
In fact, I dare to say that _most_ modern day capacitors are of a lower quality than those that were used 30 years ago. There is a reason why they survived this long....

Bob's story about the Big Blue is there only to scare people and sell Big Blue's because IF he would be consistent about it he would include the big filter caps in his cap-kits, but he doesn't because he _knows_ they almost never die.

Don't get me wrong Bob is a great guy and an excellent source for parts for our hobby and yes I am one of his regular customers...but let's keep things in perspective.

Yes I am sure many Atari's have been resurrected with a fresh "Big Blue", but relatively to the number of still running machines it's not going to be a huge percentage.
 
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Of course Bob recommends replacing them all (even the good one's) because he SELLS them...car sales men recommend replacing your car too...

And we are just some nitwits who know nothing and have no experience at all.....

Replacing an original Big Blue that measures out good with either a capable ESR meter or the ripple AC measurement is a waste of money and an unnecessary load of the environment because you throw away a perfectly good cap.
In fact, I dare to say that _most_ modern day capacitors are of a lower quality than those that were used 30 years ago. There is a reason why they survived this long....

Bob's story about the Big Blue is there only to scare people and sell Big Blue's because IF he would be consistent about it he would include the big filter cabs in his cap-kits, but he doesn't because he _knows_ they almost never die.

I wasn't going to blaspheme, but...

+1
 
+1 more.

I've been doing this as a hobby for over 20 years. I've never replaced a 'big blue', but I did BUY one to put into a Crystal Castles. Didn't need it- it's still in the parts box.

Same here. Bought one to have 'just in case.' Never used it. Still in my parts box.
 
Lucky you guys. Out of 5 Atari cabs I have repaired, 3 were big blues. Maybe it's environment too though. Games being stored for 10 years in a barn does odd things to parts.
 
Have one in my parts box too and I installed one in my SW cockpit because I was a newbie then ;) It works fine and it has a quality look and feel, no doubt about that.

I still love Bob for plenty of other stuff, don't get me wrong but the Big Blue and general "replace all caps" story is simply not true.
 
Lucky you guys. Out of 5 Atari cabs I have repaired, 3 were big blues. Maybe it's environment too though. Games being stored for 10 years in a barn does odd things to parts.

Location also has a big influence. If cabs have been in humid and hot area's, maybe sea air..(New Orleans ?) it can well be that the caps have suffered more than in an area with moderate temperatures like north west Europe where I live.
 
Had to chime in. Only have 3 machines with that setup. My atari Football came with two and I had no esr meter. Found out one of them was bad but replacement was included. So from 1978 to nowish is still a good service run.
 
Of course Bob recommends replacing them all (even the good one's) because he SELLS them...car sales men recommend replacing your car too...

And we are just some nitwits who know nothing and have no experience at all.....

Thanks for saying this. I didn't have the heart to bust anyone's Bob-bubble.

The whole Big Blue Myth thing is a little out of hand. I have replaced one big blue... back before I knew my ass from a hole in a Battlezone. I still have the one I took out, and there's nothing wrong with it. I keep it as a spare on the off chance I ever find an actual bad big-blue.

I'm a big advocate of measuring the ripple voltage (or ESR, if that's your thing) and only replacing bad parts.
 
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