Please help me fix this 2600

[tokumaru]

Hello everyone,

 

I hope you can help me out with this. I have a 2600 that's not functioning properly. I can get it to turn on, but the image has too much interference, so much that it's kinda hard to play games. The way the objects behave on screen appears to affect some of the noise. For example, scanlines where the ball is active are distorted differently. Sometimes TIA objects (playfield pixels or the players for example) will flash white and flicker. When this starts hapenning the console will either reset or shut down. I can't play for more than a couple of minutes before the severe glitches and shut downs start hapenning.

 

Does that sound familiar by any chance? Is that a common problem? Is my TIA fried for good or is there any hope?

 

I already have a working 2600, both are the Polyvox model sold in Brazil, but the defective one looks more similar to the original console internally (2-sided PCB, metal shield, external power supply), while the working one looks more cheap (single-sided PCB with completely different layout, no shield, built-in power supply), so it would be nice if the broken one could be fixed to become my primary console (although it's ironic that the well built one is the one that's defective).

 

Thanks for the help!

[A.J. Franzman]

Sounds like possibly a bad voltage regulator.

[tokumaru]

Sounds like possibly a bad voltage regulator.

Really? That's the three-legged thing that goes on top of a piece of metal, isn't it? How could I go about diagnosing/verifying this?

[A.J. Franzman]

Put the black "common" lead of a voltmeter on the middle leg. Then place the red lead on each of the other two legs. One leg should read in the range of 9 to 15 volts DC, and the other should read between 4.75 and 5.25 volts DC. If the "high" (input) side is too low, the problem is elsewhere, but if the input side is OK and the output side is outside the range I mentioned, the regulator is bad.

 

On the other hand (for anyone else who may find this post later), if the output leg of the regulator reads at or near 0 volts, then the problem MAY be another component or solder flaw causing a short circuit. If replacing the regulator has no effect, then this is certainly the case.

Edited May 7, 2010 by A.J. Franzman

[tokumaru]

Thanks for the tip, I'll check this tomorrow!

[tokumaru]

I checked the regulator and the voltages look fine. The input is a little low I think (a little under 9V), but the output is almost exactly 5V.

 

Here is a video displaying the problem:

 

http://www.youtube.com/watch?v=uCznqX9TuYM

 

This is the game running without any input. Notice how there are several rendering problems (easily visible in the escalator for instance) in addition to the interference. I didn't turn the console off at 0:53, it's doing that on it's own.

[A.J. Franzman]

Sorry, I have nothing more to add. I'd need to have the console here to go any further.

[tokumaru]

Sorry, I have nothing more to add. I'd need to have the console here to go any further.

That's OK. I appreciate the help. I posted the video hoping that someone has seen something similar to this, let's see if that's the case.

[BigO]

Nothing definitive from me, just some questions in the vein of "shotgun"or wild guess approach":

 

Does anything happen to the picture when you shake or hit the console, power supply, RF cable or jiggle the cartridge? Maybe there's a loose connection somewhere.

 

Was the console in failure mode when you tested the input voltage? What's the current rating on your power supply? Maybe it's overloaded and dropping out when it gets hot.

 

Does the unit have socketed chips? If so, I'd pry them up a bit then "re-seat" them.

 

Does the picture come back immediately if you cycle the power after a failure? I don't know what type of power switch it has, but maybe it's not making good, consistent contact.

Edited May 12, 2010 by BigO

[Badfinger]

Other troubleshooting questions:

 

Did you try another cable from the unit to the TV?

Do the controls work when that visible picture is there?

Does this on every cartridge?

Slot contacts been cleaned?

[tokumaru]

Does anything happen to the picture when you shake or hit the console, power supply, RF cable or jiggle the cartridge?

I messed with the RF cable, and nothing changed... Jiggling the cartridge appears to freeze everything.

 

Was the console in failure mode when you tested the input voltage?

Yes.

 

What's the current rating on your power supply?

I don't know, but it's the one that came with the console, with the 'Atari' brand on it.

 

Maybe it's overloaded and dropping out when it gets hot.

I considered this, but I tested with a generic power supply set to 9V and the console behaves exactly the same.

 

 

Does the unit have socketed chips? If so, I'd pry them up a bit then "re-seat" them.

Only the CPU isn't socketed. I have re-seated the TIA, but will try the RIOT as well.

 

Does the picture come back immediately if you cycle the power after a failure?

Not really. When it does it's just for a split second. I really have to wait a couple of minutes or so (so it cools down?) in order to power everything up again and actually get a picture for longer than half a second.

 

Did you try another cable from the unit to the TV?

Yes, same thing...

 

Do the controls work when that visible picture is there?

Yes, I would be able to play normally if it weren't for the constant resetting.

 

Does this on every cartridge?

Yes, every cartridge I own, and are known to work fine on my other console.

 

Slot contacts been cleaned?

No, but I can do that.

 

 

Thanks for the ideas guys. It seems this isn't an issue as common as I first thought it was...

[BigO]

It does sound like you might have some issues with the cart slot. Get that cleaned up really well and see what happens.

 

Beyond that, it also sounds like you could have a heat related failure. Have you tried playing games in the freezer? This could be caused by a bad solder joint or a bad component. I'd first do a thorough inspection of the solder joints and reflow any that look suspicious in any way. Based on what the picture shows, maybe it's a problem somewhere around the RF modulator?

 

You could try heating sections of the board with a hot air gun (or blow dryer) to see if you can induce the failure faster. Or you could hit sections of the board and specific components with freezer spray when it's about to fail to see if you can bring it back.

[tetrode kink]

If you don't have any freezer spray, put an ice cube in a sandwitch bag and touch it to components and chips. The advantage that has over the spray is that it only costs you the water and the electricity to run your refrigerator.

 

-tet

[Animan]

I had a similar issue to yours. It turned out to be a bad RF Box. I recommend getting this item. Plug the 2600's cable into this, and plug that into the TV. If that doesn't work, then it's a problem with the 2600.

http://www.radioshack.com/product/index.jsp?productId=2062632