Troubleshooting a dead 2600

[madmartian]

I got a DOA 2600 6-switch second edition. The power supply works, so it's the console. No picture or sound at all - it's dead. I have it plugged directly in to a composite video monitor, so I am not using the RF modulator. Is there a web site with troubleshooting tips or does anyone here have a list of things to check for on a DOA console?

 

Thanks.

[King Asmo]

I'm also looking for a good troubleshooting page. I have a dead system or two.. I also seem to have a few systems where everything works but the sound. Instead of getting sound, I just get the "snow" sound.

[Ian Primus]

If you connected it directly to a composite video monitor, it won't work. Although the plugs are the same size, they carry different signals. You must use an RF box and a television set. A composite monitor (such as those meant for Apple II series computer) will NOT work. If you don't have the RF box, go to Radio Shack and get a Coaxial(F-type)to Female RCA Adapter, it should be about $3. It works much better than the RF box ever did. For more info, visit: http://www.atariage.com/howto/connect.html

 

Ian Primus

ian_primus@yahoo.com

[+-^CrossBow^-]

also if you do actually hook it up via RF correctly and still get nothing then here are some things to check for:

 

1st define Nothing (IE Black screen...or still snow/white noise)

2nd if you get a black screen then that means the unit is at least seeing something. So then you go to the next step which is:

3rd if you have other 6 switch units that do work, then swap out the switch panel board by simply unplugging the ribbon cable from the main metal box where the cart connector etc are located. Then try the 2600 again. If you not have a working picture and all is well, then you can rest assured that the Main guts of the 2600 in the metal box are fine. So onward to this step:

 

If you get a black screen and nothing else when you power on the system, then this usually indicates that the RF circuit is thankfully still working. The reason for the black screen is that the voltage isn't being supplied to the main logic in the metal box, in this case to the Stella chip..etc..

 

I have found 2 2600s in my time that both had the same problem. It turned out to be the cheap little +5 voltage regulator that costs all of about a $1.50 or so to replace. The +5 regulator is a 7805 type even though on the old 6 switch units Atari used their own PN and hence it isn't labeled this way..but it is a 7805. That regulator is usually located in the lower left of the switch board clipped onto a small heatsink. On the newer 4 switch units it is still in the lower left corner of the board and usually screwed onto a big metal square area on the mainboard.

 

If you unfortunately still get nothing after doing this swap then the problem is must be in the Metal box. So any of the chips could be bad or loose as well as any of the coponents inside.

 

Just a few things to check. Also for anyone who has picture but no sound, then either the RF circuit needs to be adjusted on the coil or...possibly the TIA chip has problems.

[madmartian]

quote:

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Originally posted by Sark:

http://www.atariage.com/howto/connect.html

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This web site has a link to making adjustments with a soldering iron to your Atari 2600 *JR* to allow direct connection to a composite monitor. Do you know of another site that has similar instructions for the 2600 (not jr)? Thanks for the info.

[madmartian]

Ok, I have it hooked up correctly now (in to the VCR antenna jack, out from video jack)and I am getting a picture - a shakey flickering picture. I tried the channel A/B switch on the console and channels 2,3, and 4 - 3 works best but is still nasty. Any idea what's next?

[Ian Primus]

If you are using an RF box, junk it and get the adapter. It's only $3 and worth every penny. Double-check to ensure that all the connections are made well, and that you have used sheilded cables. A crappy cable can cause a bad picture. In particular, check the cable that leads from the back of the composite monitor to the VCR (if using this setup). If you are using a cheap audio cable for this, this is not good enough. Get a sheilded cable, or at least a decent quality audio cable. Also, if you are using a TV set, make sure that the tuner knob is set correctly. Check the fine tuning adjustments. Also, try jiggleing the knob, that sometimes helps too. If you are using an old enough VCR to hook the thing up through, it should have a flip down panel with itty bitty dials in it to set the channels with. Try adjusting those. If all else fails, you can do the composite mod, easy if you are good with a soldering iron. There are instructions for doing this for other models, look around on the 'net.

 

Ian Primus

ian_primus@yahoo.com

[madmartian]

Ok, I did the composite mod. WOW! What a difference! Looks great! Just one slight issue - some frequencies of sound cause some bending in the video, like the tank engine sounds in "Combat". Any suggestions for correcting this? I assume I need to do something about shielding, but what?