Atari Football

greenacarina

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Just digging into my newly-acquired Atari Football for the first time. Everything seems to work except for a monitor issue. Picture rolls and is wavy. The monitor is a Motorola, and looking in the manual it appears there is a little metal can (variable cap?) labeled "Horizontal Osc" which I assume should control my rolling. I can't seem to get the right tool in there to adjust it. Most of these that I've seen in the past use either a phillips or flathead. It's a little tough to see in there, but it sure looks like a round hole. Any advice appreciated!

Thanks,
Chris
 
Dont stick a metal tool in there! Despite the inductance turning whatever tool into a virtual soldering iron, theres some high voltage involved too! Metal tools is usually a bad idea on a monitor.

That said...your problem lies in a huge metal can capacitor. Theres been a rash of them going bad and causing waviness. Look up the recent posts on bw monitors with waviness issues.

That cap is a multicap so youll need to get a few different caps to replace it, and i think someone here even had them.

Hope this helps...just got back from the shore at 1:30am and i have work tomm.
 
Dont stick a metal tool in there! Despite the inductance turning whatever tool into a virtual soldering iron, theres some high voltage involved too! Metal tools is usually a bad idea on a monitor.

That said...your problem lies in a huge metal can capacitor. Theres been a rash of them going bad and causing waviness. Look up the recent posts on bw monitors with waviness issues.

That cap is a multicap so youll need to get a few different caps to replace it, and i think someone here even had them.

Hope this helps...just got back from the shore at 1:30am and i have work tomm.

Assuming this is what Bob Roberts refers to as "Big Blue"?
Haven't taken it off yet, are there more caps in that vicinity that I will need to replace?

Chris
 
Before going any further, I'd assume you need to:
a) Replace the big blue/filter cap
b) Do a cap kit on the monitor, check for bad solder joints.

I restored a Football and recapped the monitor.. it ended up having a great, crisp picture after that. It's a given in any Atari cabinet I come across to replace the big blue. Common failure/problem point and nice to get that out of the way.
 
Just digging into my newly-acquired Atari Football for the first time. Everything seems to work except for a monitor issue. Picture rolls and is wavy. The monitor is a Motorola, and looking in the manual it appears there is a little metal can (variable cap?) labeled "Horizontal Osc" which I assume should control my rolling. I can't seem to get the right tool in there to adjust it. Most of these that I've seen in the past use either a phillips or flathead. It's a little tough to see in there, but it sure looks like a round hole. Any advice appreciated!

Thanks,
Chris

You need a hex/allen wrench type tool, but that doesn't sound like your problem.

Edward
 
You need a hex/allen wrench type tool, but that doesn't sound like your problem.

Edward

After doing some more research, it seems that Big Blue is the likely culprit. Just received that as well as the parts to rebuild my trackballs from Bob Roberts. Will find out soon if that's the only problem. As a side note- I don't know if enough good can be said about Bob Roberts. I emailed him on Sunday night, got a reply (late at night, too) with a total. Mailed the check Monday morning, got an email that he had shipped my stuff Monday afternoon (before he got my check, mind you), and it showed up in my mailbox halfway across the country on Wednesday!!! AND he sent me a set of small wirecutters as a gift!
Not only does he have damn near everything for vids...and a wealth of knowledge, his customer service is way above-and-beyond. If you're not buying your parts from Bob, you really should be.

Chris
(STOKED on my new game!)
 
Well, good news and bad news. My trackballs work like brand new, but after installing the new Big Blue cap my monitor still has issues. Just taking a look at the monitor board it looks like someone may have done a cap kit on it at some point in the not too distant past. What would be my next course of action?

Thanks,
Chris
 
Do you have pics of the problem? I know on the B&W games sometimes what may look like a monitor problem is a PCB problem. Download atari's The Book, it has some decent troubleshooting for mointors in it. It's what I used to get my Motorola working in my Gran Trak 10. - Barry
 
Did they replace the large silver can capacitor on the monitor? That's the main filter, it's actually a multi-section cap, several capacitors in one. When they go bad, the picture gets this wave through it.

You can isolate the problem to the monitor by feeding in some other video signal, or feeding the game's video elsewhere. Black and white arcade monitors actually just take regular composite video. The molex plug carries AC power to the monitor, as well as the video signal. Check the wiring diagram in the manual to see which pin is which. There will be a video line, and a video ground. You can make up a lead to go from that plug to an RCA connector. Center pin is video, outer ring is video ground. Plug that into a the composite video input on a television set, and see the game's video on that screen. Or, patch the signal from something else (like a Nintendo) into the arcade machine's monitor. This will help rule out if it's a board problem or a monitor problem.

For a test lead, a length of two conductor wire with some bits of a paper clip soldered to the end work. You can jam the paper clip pins into the back of the molex connector that goes to the monitor. To test the game's video on something else, unhook the molex from the monitor. To test some other signal on the monitor, plug the molex into the monitor, and unplug the edge connector from the game board.

-Ian
 
Thanks for all the tips! I will take some pics when I get home and try to document the problem as best I can. Will try the troubleshooting techniques and see what I get.

Chris
 
OK, here are a couple pics. These were taken from the access door side of the machine. Picture is rolling left to right. Let me know what you think....


football002.jpg




football001.jpg
 
Looks like you've got foldover, and sync issues. Did you try connecting the video to a television, or something else to that monitor, to rule out any potential gameboard issues?

-Ian
 
Looks like you've got foldover, and sync issues. Did you try connecting the video to a television, or something else to that monitor, to rule out any potential gameboard issues?

-Ian

It appears I've got something going on that is NOT the monitor!! Hooked this game up to an old computer monitor and it has the same issue. Something wrong on the main circuit board I guess. Any kind of troubleshooting a guy could do with a multimeter and a logic probe??


Thanks!
Chris
 
It appears I've got something going on that is NOT the monitor!! Hooked this game up to an old computer monitor and it has the same issue. Something wrong on the main circuit board I guess. Any kind of troubleshooting a guy could do with a multimeter and a logic probe??

Ah hah! Now, just to be doubly sure that your monitor is working, hook it up to something like a Nintendo or a VCR, and see how well the monitor is working.

As for the game board problems, as long as you have a logic probe, you should be able to fix it. Let me read the manual and see what the video circuits look like to give you some pointers.

-Ian
 
OK, from looking at the pictures, it appears that your horizontal counters are working, since the image is fully scanned from the left of the screen to the right (referring to the monitor as if it were oriented like a television). But, it appears that you have vertical foldover, as if the vertical counters aren't working properly at some point. When you look at the image on the computer monitor, is the bottom or the top folded over?

Debugging this circuit is easy and straightforward with a logic probe. Use the probe to check the output pins of the chips at M5 and M6 (pins 14, 13, 12 and 11 on both chips). They should all be pulsing.

-Ian
 
OK, so now it looks like I've got 2 problems going on. I plugged in another input source (PS2) to the monitor....it's not scrolling like the game was doing before, but still curled over at the edge and picture is split in the middle. Will test the pins on M5 and M6 next, but it seems like I'm chasing 2 problems now....a board problem and a monitor problem.

Chris
 
Grrrrrr! Things are changing in a very random way. Now the curl is gone, but the picture does not go to the edges of the screen. The image is split in the middle, but overlaps itself. And some of the characters seem to be distorted. Trying to connect my logic probe is giving me fits as well. I found 5 vdc at the positive end of a smaller capacitor, and neg at the large ground trace that runs the perimeter of the board....I get nothing! WTF?!?!
The only thing that's changed since my first pictures is that I've removed the game board from the cabinet. As the game stays on longer, the picture gets narrower.

Here are some pics of what the screen looks like now-



football2002.jpg



football2001.jpg
 
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