Troubleshoot new 2600

[DoctorFunk]

Hi all, been lurking here for a while, but this is my first post. Just picked up a "light-sixer" model 2600 yesterday from an owner who hadn't tested it yet. I immediately grabbed the RCA to F adapter from Radio Shack and plugged it into my HDTV's coax input. Problem is that the screen will change static pattterns somewhat, sometimes even getting to a black screen but it will never display a game image after testing multiple carts. Occassionally if I manipulate the power where it plugs into the back of the system I can get a second of sound to come out, sometimes sounding like just static noise, and once in a while putting out the actual game sounds. I tested the unit on 2 TV's, unfortunately both are Samsung HDTVs and I don't have any older console sets around to see if that might be a problem.

 

Picked up a new universal adapter after reading a ton of useful troubleshooting posts here last night. I set it to the correct settings (9 V, positive tip, with the adapter capable of up to 1700ma) and that didn't change anything. So I guess the old power supply probably wasn't the problem. Opened up the unit and didn't notice any gross corrosion, seemed to my very untrained eye that everything was still attached where it should be on the motherboard. Checked the RF cable and didn't see any gross abnormalities. Even tested it with a yellow video RCA cable I had lying around with no changes (it wasn't seated properly though due to the length of the jack where it plugs into the 2600). So now I feel like I've done some simple tests to check whether the power supply or RF cable is the culprit with no solution.

 

My gut feeling is that it is something with the system's power, as the flickers of different static, black screen, or sound all come when I manipulate the power supply where it plugs into the system. I've messed with the on/off switch and while it's not the firmest switch on the system it doesn't seem to change anything at all and it's not overly loose in my estimation. I'm open to any ideas on what else I could do to test the system or get it working, or even if I just need to chalk it up to it being a goner. I could also try to test it out at a friend's house to see if my HDTVs could not be picking up the signal or anything (did try to run the RCA to F coax through a VCR to amp the signal with no luck--didn't even budge off the VCR blue screen). I've been dying to get a 2600 for a few years now and am dying to play this baby ASAP!

 

Thanks in advance for any help you can offer. I'm amazed at the level of knowledge on this board!

[Ian Primus]

Sounds like you're not getting power. You've already ruled out the power supply itself, so it's time to rule out two other real simple problems. And I'm sure you've already tried both positions for the channel selector on the Atari.

 

Take the console apart (if it's not still apart), and look at the back of the circuit board where the power socket is mounted. Ensure that the solder connections are good, and aren't cracked or loose from the board. Resolder these if necessary. Then, look where the power switch is soldered to it's board - and check it's solder pads carefully. I've fixed more than one 2600 by simply resoldering these points.

 

With no game inserted, you should ALWAYS get something on the screen when you turn it on. It should be either a solid black screen (with a faint grey line down the left), or a screen with vertical lines of color. If you get this, then the power supply is working.

 

Clean the game cartridge slot. Look at where the game plugs in. There are two tabs, one on either side, and two small holes, and the long slot in the center. Using a small screwdriver or similar tool, insert it into one of the small holes - this opens the cartridge slot. You should see the pins inside.

 

Get a piece of computer paper and fold it over a couple times until it's the thickness of the circuit board in the Atari. Cut it to the same width as the cartridge circuit board slot. Gently insert the folded edge into the opened cartridge slot, and firmly press it in, then pull it out. You should see a bunch of little dark lines on the paper. Repeat with a clean bit of paper until you don't see any more dirt coming off.

 

Clean a cartridge. Using the same small tool, open the door on the cartridge and push it back. Dip a q-tip in isopropyl alcohol and clean the gold contacts you've just exposed. Scrub good and hard, you can't hurt it with a q-tip. Repeat until the black crud stops coming off.

 

Once it's dry, plug it in and try it out, and let me know what you get.

 

-Ian

[DoctorFunk]

Thanks for the tips. I inspected the solder points and didn't see any obvious cracks, but there was some yellowing at one point for the on/off switch. I'll probably go ahead and plan on resoldering the points associated with the power socket and on/off switch this weekend (need a buddy to teach me how to do it) unless that would cause any harm to the system.

 

I also cleaned out a cartridge and the cartridge slot. While it didn't improve the picture much (still mostly a black/grey screen with slightly haphazard horizontal grey lines scrolling vertically), I did manage to get a solid 10 seconds of sound out of my Pac-Man cartridge. Not a huge improvement, but I'm willing to take baby steps on this project. Still seems like the power supply is very temperamental and will completely loose power (screen goes back to plain static) just from barely touching the entry into the power slot. Does that sound like a bad soldering point at the power socket?

[shadow460]

Either bad solder at the socket or perhaps a bad socket. While in there you might try cleaning out the power switch with a Q tip and alcohol. Just flip it one way to aloow the q tip in, then flip it the other way and repeat. If the joints around the power switch are loose or if that needs cleaned out, go ahead and clean/resolder all the switches while you're in there.

[Ian Primus]

It does sound like a bad solder joint at the power socket - if jiggling it sometimes results in sound/picture. Try gently rocking the connector back and forth in the socket, see if you can find a spot where it works, and hold it there - if you can get it to stay working, then you've found your culprit. Similarly, with the power switch, by pressing in and fiddling with it, slowly moving it around, you should be able to get it to work for a bit.

 

I've seen relatively few very dirty power switches on the 2600's - and none causing a totally dead condition, ususally they just require a bit of jiggling to work. Not like the Colecovision, with it's extremely failure prone switch. Start by resoldering the switch and power socket, it's easy and can't hurt.

 

If you can get the Atari to stay on when rocking the connector in the socket, and you've already resoldered it, then it could very well be a faulty power socket. Again, not particularly common on the 2600 - bad solder joints are far more likely - but it's possible.

 

The best way to check would be to measure voltages inside the Atari - do you have, or have access to, a voltmeter? If you can't get it to work for more than a second, and the power connector/switch is not a problem, then you could have a bad voltage regulator. If you have a voltmeter, you can check this very easily.

 

Let us know how you make out - and if you can get ahold of a meter, I can walk you through testing some things.

 

-Ian

[DoctorFunk]

So, thanks to the great advice you guys gave me I went to work on the system again today. My buddy and I found a loose solder point on the power socket, which we resoldered. Also cleaned out the on/off contacts with alcohol. The power supply now works great and we have consistent power in the system now. Upon hooking it up to his HDTV, however, we could see a game image (which I had never before seen on the two HDTVs I tested it on at my place) but the color was off and the picture seemed to scan almost diagnonally. The sound worked perfect.

 

We checked solder points associated with the RF input on the motherboard but didn't notice any problems. We soldered together a new coax cable with an RCA jack that we ground down to the right dimensions to plug into the Atari. The new cable didn't change the picture at all, so it seems like the original RF cable is okay. We also cleaned the catridges we were using to test with isopropyl alcohol and cleaned the cartridge slot with alcohol and then emory cloth. No changes. Decided to call it a day and check with the folks on this board to see what the next step might be.

 

Took it home and hooked it up to my Samsung HDTV and found that where we had seen a game picture at his place on both channels 2 & 3 (when switching over on the system) all I got at my place was a change in the nature of the static from normal static to a mostly black background with some white marks scanning vertically. Sound still works fine. Now I'm fairly confused as it doesn't seem to be any of the easier fixes and we haven't noticed any major issues with other solder points on the board. Any ideas for further testing I can do, or should I just chalk it up to a bad deal and keep an eye out for another system? Thanks again for all of the help, I really appreciate it.

Edited April 4, 2009 by DoctorFunk

[Ian Primus]

So, thanks to the great advice you guys gave me I went to work on the system again today. My buddy and I found a loose solder point on the power socket, which we resoldered. Also cleaned out the on/off contacts with alcohol. The power supply now works great and we have consistent power in the system now. Upon hooking it up to his HDTV, however, we could see a game image (which I had never before seen on the two HDTVs I tested it on at my place) but the color was off and the picture seemed to scan almost diagnonally. The sound worked perfect.

 

Did the game play? I mean, were you able to start a game, and move the joystick around, and see/hear it working?

 

Took it home and hooked it up to my Samsung HDTV and found that where we had seen a game picture at his place on both channels 2 & 3 (when switching over on the system) all I got at my place was a change in the nature of the static from normal static to a mostly black background with some white marks scanning vertically. Sound still works fine.

 

I've seen the opposite problem, where you get picture but no sound. It could be the way the AFC circuit in your TV detects the carrier. Try adjusting the fine tuning knob on the TV, and see if you can get the picture to come in - even if you lose the sound. Since your HDTV is unlikely to have fine tuning - try it on another set.

 

On the Atari's board, there are two controls. One is a potentiometer you can turn with a small flathead screwdriver. This adjusts the color - and won't help you here. The other is a tall (usually red) device - it's a variable inductor that affects the sound tuning. You need to adjust this with a PLASTIC tool (a metal allen key will break it). Adjust it by gently turning the slug back and forth.

 

The only thing I can think of that could cause the problem you're having (assuming the RF modulator in the Atari is good), is that your TV's Automatic Fine Control circuit is locking onto the audio subcarrier, which is slightly off, an thus not picking up the picture properly. Again, this is a guess, since I'm not too familiar with the latest TV sets.

 

Fiddle with the control a bit - you may have to flip up and down between channels as you do this, because you want the TV to lock back onto the signal each time.

 

It's worth a shot...

 

-Ian

[shadow460]

Did you actually open the RF modulator? If so, make sure it's closed back up right. I grounded the board in mine and it wouldn't work that way.

 

I'm still thinking that reflowing the entire thing would help. It certainly could not hurt, especially since you will be in there doing it anyway within the next couple of years. If one joint has already come loose, others are likely to follow.