Atari 2600 JR1 - Screen goes to snow after 1 minute - power light stays on

[psycoustic]

Hi there - I was wondering if someone could shed some light on the below issue. I found one topic on this forum that refers to a similar issue, however the console that is being discussed there is a vader model:

 

http://atariage.com/forums/topic/241061-atari-2600-picture-cutting-out-after-a-few-minutes-of-gameplay/

 

The issue I'm having with my Atari 2600 JR1 (gen 1.) is that after about a minute, the screen slowly starts fading and turns into snow. The power light remains on.

Initially, any game I try works absolutely fine and I cannot seem to detect interference or anything.

Once I unplug the AC adapter from the wall, leaving the power switch in the ON position, the power light slowly fades and is completely dimmed after about 40 seconds. If I wait for about 2-3 minutes, I can power the console on again and play for a little and then will go off again (snow screen) after about 40-50 secs (sometimes a bit longer).

 

I measured the Adapter and it outputs 12.4 volts (DC) and 286 mA (altough the label claims it should be 9V out and 500 mA). I am looking for a different adapter but I am not entirely sure if that would cause such a problem.

 

Could this be a faulty RF modulator?

Just wondering if anyone has any suggestions I could try else.

 

Many thanks

[+SmittyB]

Sounds like your typical bad capacitor problem BUT it is a 2600 so I'd also try tuning your TV after it has faded out as it could be that it's still running but the frequency is shifting enough to kill the picture. My 7800 used to go grey then flicker out until i slightly changed the tuning on the TV so that it can handle the picture from both a cold start and while warm. Use whatever fine tuning feature your TV has as the channel finder will probably not do a good enough job at getting you the ideal tuning.

 

As for the adapter, those power supplies will always give a different rating if you just test them as the '9V 500mA' is their rating under load. I think 12 volts is about right when you're just testing it.

[psycoustic]

Sounds like your typical bad capacitor problem BUT it is a 2600 so I'd also try tuning your TV after it has faded out as it could be that it's still running but the frequency is shifting enough to kill the picture. My 7800 used to go grey then flicker out until i slightly changed the tuning on the TV so that it can handle the picture from both a cold start and while warm. Use whatever fine tuning feature your TV has as the channel finder will probably not do a good enough job at getting you the ideal tuning.

 

As for the adapter, those power supplies will always give a different rating if you just test them as the '9V 500mA' is their rating under load. I think 12 volts is about right when you're just testing it.

Thanks for your suggestions. I tested a few other 9V - 500 mA adapters and they all output around 12 V so I suppose it's normal.

 

At this point I'm not getting a picture at all anymore unfortunately. It still powers on but that's it.

I'm considering just getting a cap kit and getting the a/v mod kit as well but I'm surprised to see how pricey that still is. Kind of sucks since I picked up this 2600 for only $5 at a thrift store

Oh well!

 

 

[+nanochess]

I think is the TIA you should replace it.

[mojoatomic]

Always start at the beginning. Power and filtering. Straighten out the caps and VR, then move to RF - check pin 3 on the modulator and see what's going on. If you create a good foundation to work with, the repair will come easily :-)

[zylon]

sounds like either a cap or a bad trace opening up after it heats up