Atari VCS / 2600 (6-switch) not working correctly

[zezba9000]

Have an Atari VCS 6-switch that will work fine for 1-sec (literally) then just go into some failed state.

 

<<< EXAMPLES >>>

Turn on system & I'll see a good screen

 

1 second later get this.

 

 

Same kind of thing with a different game (and every other game I've tried so far)

 

 

Anyone know what this might be?

FYI I replaced 4.7uf-32v caps & 2200uf-16v cap. No change.

I also tried replacing transistor in RF module but that didn't help.

Edited March 25, 2021 by zezba9000

[+DrVenkman]

15 hours ago, zezba9000 said:

I replaced 4.7uf-32v caps & 2200uf-16v cap. No change.

I also tried replacing transistor in RF module but that didn't help.

From what you’ve done, it sounds like you’re shotgunning. Not the best approach. Go to Atarimania and download a copy of the 2600 Field Service Manual and work through the symptom checklists.

 

Do you have a multimeter? If so, what is the output on the voltage regulator? Since this is a six switch unit, all the chips will be socketed. So … first clean the cart slot with 90% iso or electrical contact cleaner. Next, lift and reseat each chip. If there is obvious corrosion, remove the chips and clean them with iso or contact cleaner and  a nylon brush. Reinstall the chips and try again. 

 

 

[zezba9000]

4 hours ago, DrVenkman said:

From what you’ve done, it sounds like you’re shotgunning. Not the best approach. Go to Atarimania and download a copy of the 2600 Field Service Manual and work through the symptom checklists.

 

Do you have a multimeter? If so, what is the output on the voltage regulator? Since this is a six switch unit, all the chips will be socketed. So … first clean the cart slot with 90% iso or electrical contact cleaner. Next, lift and reseat each chip. If there is obvious corrosion, remove the chips and clean them with iso or contact cleaner and  a nylon brush. Reinstall the chips and try again. 

 

 

I cleaned cartage port & the removable chips with 99% isopropyl alcohol (first thing I did).

The voltage regulator is producing 5v & 10v is being fed into it.

I will clean again to be sure but stuff wasn't super dirty. I will also see if my Sears 2600 Telegames system chips can be used to confirm if the VCS has bad a RIOT chip etc.

[+DrVenkman]

1 minute ago, zezba9000 said:

I will also see if my Sears 2600 Telegames system chips can be used to confirm if the VCS has bad a RIOT chip etc.

The chips are completely interchangeable between the systems, assuming your Sears machine is socketed. Another factor to consider is a bad socket. Make sure there are no damaged or corroded socket contacts (“wipes”).

[zezba9000]

On 3/25/2021 at 2:41 PM, DrVenkman said:

The chips are completely interchangeable between the systems, assuming your Sears machine is socketed. Another factor to consider is a bad socket. Make sure there are no damaged or corroded socket contacts (“wipes”).

The issue was the "MOS Technology R6532" RIOT chip.

Seems like both the R6532P & R6532AP will work.

[+DrVenkman]

5 hours ago, zezba9000 said:

The issue was the "MOS Technology R6532" RIOT chip.

Seems like both the R6532P & R6532AP will work.

Good news then - 6532 RIOT chips are fairly common and Atari used them in lots of stuff, notably Atari 8-fit computer disk drives. There are a few different companies that made the chip under license. The most common ones I see are Rockwell, though there are others out there. The one in my Sears Heavy Sixer is a Syntertek chip from 1977, for instance. They’re interchangeable between manufacturers.