Problem Atari power supply help

[Body pop]

I checked at the power supply (big connector plug unplugged )
I never actually checked with that plugged In as couldn’t get multimeter in there
So I would need to follow those points you showed me to somewhere I can get the multimeter on it then

 

[Ace`]

You can check at the power supply with the plug plugged in and power off to see if the resistance is very low, you will then know you have a short or not. You just don't know what's causing it this way but it's a start.