Any Atari 720 Guru's In NJ Area?

machfelon

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I now have 13 games in my collection. 14 this week after I pick up my PC10 from EagleTG.

They all work (Knock on wood) accept my Atari 720.

Game boots no problem. Joystick does not work. Skater does not move. There is an issue where I am missing nearly a volt between the switcher and the PCB. I jacked the switcher up so that the PCB is getting correct voltage and it still does not work. I've traced the connections and they appear intact. Dont know what to do. I hate having games that dont work so this is my last call to try to get it fixed. I have beer, $$$ or parts for trade :) or a mixture of them all.

Please help me fix befoer I have to trade a grail away.
 
where are you measuring the voltage on the PCB? You cant be losing a
volt in 3ft of wire unless you have some crazy corrosion/resistance.

How is the edge connector on the PCB? Any dark spots in the wiring
harness connectors?
 
I measured voltage on the bottom PCB (believe its the video one) but thats where the power comes in. Tested it on the board and am at 4.82 (switcher is like 5.8). There is a slight brown on right side of edge connector but pins appear intact and not burnt and ive also cleaned all connectors on board.

Thats more or less a side issue. But its the damn skater not working that is the annoying part. Because the game passes all tests in TEST MODE. Just wont register movements at all.
 
If it's truly a grail, you can fix it. From what i've read, probably a good idea to replace some connectors. If .156 housings, get trifurcon pins and a crimping tool and go to town.
 
I measured voltage on the bottom PCB (believe its the video one) but thats where the power comes in. Tested it on the board and am at 4.82 (switcher is like 5.8). There is a slight brown on right side of edge connector but pins appear intact and not burnt and ive also cleaned all connectors on board.

Thats more or less a side issue. But its the damn skater not working that is the annoying part. Because the game passes all tests in TEST MODE. Just wont register movements at all.

That is a problem as that is a lot of resistance there which leads to heat which is burning that edge connector. To fix it right you must not only clean the PCB edge connector, but also replace those ground and power related crimp pins. You cannot undo the burn on those pins as they are rated for only so many wipes and the tension and plating are compromised.
 
Time to sell it to me ;)

So not any moves I thought you had some movement at one point. I'll look at the board schematics on Tuesday and see if there's a common thread.
 
Time to sell it to me ;)

So not any moves I thought you had some movement at one point. I'll look at the board schematics on Tuesday and see if there's a common thread.

I had movement once but only through test mode. Has never worked again since. I have also tried 3 or 4 different boards that attach to joystick. No change. Have also tried 2 different joysticks. The only other thing I can think of is maybe a new wiring harness for joystick but have no idea where to find one for 720.

Copious if I cant get this thing going I'll trade it to ya.
 
New connectors on wiring, reflow the board connector headers and file the pins a little... add jumpers if need be and get the voltage drop lower (<.2 volts) then test your joystick...

higher voltage without drop to the joystick may have killed the opto board, or at least be keeping it from functioning (it has leds and pickups that should operate at 5v) if its not fried...

Otherwise try to hack in another 5v source to the joystick only and see iff that works

good luck, skate or die!
- gwarble
 
+1 to this. Check the joystick board first, as it is probably not getting enough voltage. Then rewire everything. Not difficult at all, just time consuming. Pull every pin and replace it. Then take a very soft abrasive and try to get the edge of the board clean enough to give a solid connection.

New connectors on wiring, reflow the board connector headers and file the pins a little... add jumpers if need be and get the voltage drop lower (<.2 volts) then test your joystick...

higher voltage without drop to the joystick may have killed the opto board, or at least be keeping it from functioning (it has leds and pickups that should operate at 5v) if its not fried...

Otherwise try to hack in another 5v source to the joystick only and see iff that works

good luck, skate or die!
- gwarble
 
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