Author Topic: I got a Dead 720 for free. Help me get started on this project again. (Read 4545 times)

KenToad · « **on:** March 25, 2006, 04:43:04 pm »

Hey All,

I lucked out and just got handed a free 720 cabinet. Everything is in great shape, except the monitor just starts as a red screen with some wavy lines--no sound either. Anyway, the guy who owned it before apparently disconnected a few things and didn't put them back together correctly. This game didn't come with a manual, so I wonder if anyone with an original cab could take some pictures of the pcbs and various connections so that (hopefully) I can get this thing running again.

Any help would be greatly appreciated. I'll post some pictures of the box, in great shape except without sideart, later.

Cheers,
KenToad

PoDunkMoFo · « **Reply #1 on:** March 25, 2006, 06:07:18 pm »

You can buy a manual here.
http://www.quarterarcade.com/Game.aspx/6029

If you look you might find one online.

KenToad · « **Reply #2 on:** March 25, 2006, 07:34:16 pm »

Quote from: PoDunkMoFo on March 25, 2006, 06:07:18 pm

You can buy a manual here.
http://www.quarterarcade.com/Game.aspx/6029

If you look you might find one online.

I guess that would be the last resort. Atari used to send these things out free.

Did some Googling and now know that I need Technical Manual 294 or TM-294 for short.

Cheers,
KenToad

spriggy · « **Reply #3 on:** March 25, 2006, 07:56:58 pm »

Quote from: KenToad on March 25, 2006, 07:34:16 pm

Did some Googling and now know that I need Technical Manual 294 or TM-294 for short.

Cheers,
KenToad

Here ya go KT......

Kremmit · « **Reply #4 on:** March 26, 2006, 12:31:24 am »

You Lucky Bastard!

I've scored freebies, but never anything as nice as a 720. That rocks.

jerryjanis · « **Reply #5 on:** March 26, 2006, 10:18:49 am »

Jealous...

GGKoul · « **Reply #6 on:** March 26, 2006, 11:02:14 pm »

WOW!!!

Pics please!!

KenToad · « **Reply #7 on:** March 27, 2006, 05:12:40 pm »

Thanks to all who have replied. I will post pics soon, even though I have not been able to get the game running. The fuses look good and the monitor and speakers power on and the monitor is adjustable, but never gets past a red or bright pink blank screen. I've noticed that at least one of the edge connectors has what looks like a cigarette burn on one of it connectors, so maybe there was a problem with that connector being misconnected or just a power surge. I don't know.

I will post pics soon. Thanks again to everyone. And, remember, if anyone knows someone who has an original, working 720, I would love to get in touch via email and hopefully get a few snapshots of the connectors in place. I was able to download the manual. Thanks Spriggy. But it isn't really clear where all the connections belong or how to test a machine that won't go into self-test mode.

Cheers,
KenToad

RayB · « **Reply #8 on:** March 27, 2006, 05:16:37 pm »

Quote from: KenToad on March 27, 2006, 05:12:40 pm

I've noticed that at least one of the edge connectors has what looks like a cigarette burn on one of it connectors, so maybe there was a problem with that connector being misconnected or just a power surge. I don't know.

A common problem with Atari games.
I would clean the edge traces, especially the burnt one. You need good contact there, otherwise the power supply board tries and pump out more juice, thinking the voltage is too low. If the trace is too burnt, you will have to reconstruct it so you get good contact.

That's the other common problem. The power board fails.

Buy a digital multimeter. You're going to need one.

KenToad · « **Reply #9 on:** March 28, 2006, 02:03:48 am »

I may be in luck and have just emailed a guy selling what looks like a great condition 720 on Ebay to see if I can get some pictures of the PCB's and connectors. I wish my box was in that kind of shape after 20 years.

Here is the auction, if anyone is interested:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=6265344237

Cheers,
KenToad

KenToad · « **Reply #10 on:** March 28, 2006, 08:32:04 pm »

No word yet from the seller on ebay. *Edit* He has announced that he will not be around his computer for a week.

Here are the pics I promised.

Cheers,
KenToad

KenToad · « **Reply #11 on:** March 28, 2006, 08:45:37 pm »

The CP is really spiff, almost no sign of wear. I wiped off some dirt. That's about it. Also, the front lower panel is particle board. It has a kind of gnarly look to it. Get it--GNARLY dude!

I was a skater punk once, so I can say that. Anyway, the upper part of the front panel, where the CP connects, is pretty chewed up. The cab has been outside and is pretty dirty. A pretty large mouse nest was right under the coin box. So, a little mouse piss and must, probably a pretty easy cleanup, if I can get the game to work once more.

Quote from: RayB on March 27, 2006, 05:16:37 pm

Quote from: KenToad on March 27, 2006, 05:12:40 pm
I've noticed that at least one of the edge connectors has what looks like a cigarette burn on one of it connectors, so maybe there was a problem with that connector being misconnected or just a power surge. I don't know.

A common problem with Atari games.
I would clean the edge traces, especially the burnt one. You need good contact there, otherwise the power supply board tries and pump out more juice, thinking the voltage is too low. If the trace is too burnt, you will have to reconstruct it so you get good contact.

That's the other common problem. The power board fails.

Buy a digital multimeter. You're going to need one.

How would you suggest cleaning them, or should I just go and search the wiki? By Power board, do you mean CPU board, the upper one? Total noob here in this case Ray, but I appreciate any constructive comments like yours.

Cheers,
KenToad

SirPeale · « **Reply #12 on:** March 28, 2006, 09:50:59 pm »

So far, what I see:

1) the "cigarette burn" is from the pins making improper contact with the harness. Take it off, clean the pins with some fine grit sandpaper, and put it back on. You *should* replace the connector as well, but for the next little bit (little bit being less than ten hours of on-time) you should be okay for the time being.

I note that there's a switching power supply in there. Have you metered the voltage from it? Make sure it's putting out no more than 5.1 volts, and no less than 4.9.

And, finally, in the picture where your finger is, I believe that wire belongs on 'ground' but I could be wrong.

Edit: I note the -5V screw terminal is up, and I see there appears to be two wires not currently connected. Until you trace which is which (ground or -5V) don't hook either of them up. Perhaps the manual will let you know which color goes to which, I dunno why they are all brown!

KenToad · « **Reply #13 on:** March 28, 2006, 10:52:13 pm »

Thanks for looking Peale! I really appreciate advice from guys like you who have experience with this sort of thing. I posted the picture of the brown wires because I'm also not sure what to think. They were connected to nothing, but soldered together firmly. Also, those two screw terminals were both up a bit, but I screwed them up a bit more thinking that I would just try to lay the wire in there. Call me stupid. I did that and nothing happened. The manual says that green should be ground, but brown seems to be ground in at least several cases here.

I will definitely try cleaning the pins by the burn. Thanks for the how-to. Also, equally baffling is that the fan wires are not hooked up to anything and the only connectors that would seem to match perfectly are running from the monitor and hooked up to something else, which also seems to go to a couple of spade connections at the very bottom edge of the video pcb. I already tried a couple of what seemed like likely combinations and have replaced two fuses.

I went a little nuts in ignorant enthusiasm, but I don't think I made anything worse yet.

Cheers,
KenToad

SirPeale · « **Reply #14 on:** March 28, 2006, 11:13:02 pm »

Green is likely earth ground. Looking at it further leads me to think those soldered wires are ground. You'll have to screw them in to make adequate contact.

But before you do that...HAVE YOU MEASURED VOLTAGE YET? If you have a dead or underpowered power supply, all the twiggling in the world won't do diddly.

KenToad · « **Reply #15 on:** March 28, 2006, 11:43:41 pm »

I think I'm going to need some kind of how-to article to measure voltage on this thing. Also, I have to buy a multimeter. I kind of just assumed the power issues weren't happening because the monitor and speakers power up. I'm guessing that it was wrong to assume that. I can post more pictures of the power supply if that would aid you in spelling out where I'm supposed to touch the multimeter leads.

Cheers,
KenToad

RayB · « **Reply #16 on:** March 28, 2006, 11:50:25 pm »

Don't just go hooking up wires where you "think" they should go. You have to be 100% correct, otherwise you risk damage to parts that aren't already damaged.

Lindner24 · « **Reply #17 on:** March 29, 2006, 11:37:02 pm »

I have a 720 in the basement, actually two...
I am storing one that belongs to a friend and
just bought one for myself a few months ago.

If you need anymore pictures, I could probably get some for you
this weekend...

I had to take mine apart in order to get it in the house by myself,
I remember the monitor having a weird connection where there
were more pins than receptacles and it was not keyed.

I had to refer to the other game to get it connected properly.

This was right behind the access panel behind the monitor

RayB · « **Reply #18 on:** March 30, 2006, 01:02:51 pm »

*delete this*

KenToad · « **Reply #19 on:** May 10, 2007, 12:29:32 pm »

Hello, I'm resurrecting this thread, since I want to bring the project to the front burner again.

I haven't touched the box since my last post. But, what I've casually read since then makes me think that I should just buy a new Power supply and see what happens, especially since I suck at diagnosing this type of thing. I have a friend here in town who is an engineer, so I could potentially get some help here.

Anyone know what kind of power supply a 720 takes or where to get one?

Or any other suggestions ... I am hoping to put in some hours on this project this Spring/Summer. Also, the box is still dirty, so I can't wait to clean it and post some better pics showing it clean.

Thanks in advance.

SirPeale · « **Reply #20 on:** May 10, 2007, 02:32:04 pm »

Quote from: KenToad on May 10, 2007, 12:29:32 pm

I haven't touched the box since my last post. But, what I've casually read since then makes me think that I should just buy a new Power supply and see what happens, especially since I suck at diagnosing this type of thing. I have a friend here in town who is an engineer, so I could potentially get some help here.

Anyone know what kind of power supply a 720 takes or where to get one?

Before you just go replacing stuff willy-nilly, why don't you test the old power supply before just replacing it?

KenToad · « **Reply #21 on:** May 11, 2007, 11:00:38 pm »

For that, I need a multimeter and you posted earlier in the thread the values that I need to find. I'll go ahead and look at the Rat Shack for a multimeter and then I'll probably need to ask for help about where to hook it up on the actual power supply.

Thanks again, Peale.

yugffuts · « **Reply #22 on:** May 12, 2007, 09:14:29 pm »

Using a multimeter isn't hard. Google it, read the manual, and connect the leads properly. Its intimidating before you actually do it, but not a big deal. Kind of like discharging a monitor

Once you get the meter, it should only take a few minutes to determine if the power board is your problem.

Witchboard · « **Reply #23 on:** May 13, 2007, 09:10:32 am »

Do yourself a favor and buy a meter that has an audible continuity beep. You'll thank yourself later.

Rocky · « **Reply #24 on:** May 14, 2007, 10:01:14 am »

Even if you buy a new Switching power supply, you'll still have to check / adjust the voltage with a multi-meter.

So, do yourself a favor and BUY A MULTI-METER!

If you want to fix games, you have to be willing to learn some stuff. The stuff that is being suggested is mickey mouse easy to learn.

Download the wiring diagram / scematics to 720 and find out where the wires are supposed to go.

If you try to take shortcuts with this, you'll regret it.


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