Dead 6 switch Atari 2600

[seanneko]

I recently picked up a broken 6 switch 2600 which I'm trying to fix. The symptoms are no signal being sent to the TV. It just displays snow as though there's nothing connected to it.

 

I have a working 2600 Jr which I've used to confirm that my TV is tuned to the correct channel and that the game I'm testing with also works.

 

Steps I've taken on the dead 6 switch:

 

- Confirmed 5V is coming out of the 7805 regulator.

- Removed the built in RF cable and tried a different known good one.

- Disassembled all switches and cleaned with alcohol (including the channel select switch).

- Inspected for cracked solder joints.

- Swapped TIA chip between the 2600 Jr and the 6 switch. It turned out that the 6 switch's TIA was dead, although it still has the same symptoms with the working TIA installed.

- Swapped the UA3086PC from the 6 switch RF modulator with the CA3086 from the 2600 Jr's RF modulator. The Jr still worked fine and the 6 switch still had the same symptoms.

 

I'm at a loss for what else to try. Would a bad CPU or RIOT cause this problem?

[Voxel]

You can work backwards or forwards.

 

Forward: Follow the power through the circuit and find where it stops.

 

Backward: Follow from the signal output back towards the faulty component.

 

Have you tried checking the channel select switch which may have oxidised and stopped the signal.