I powered on again the newly grounded machine. The vertical bars that once covered most of the screen shrank to about 1 inch across. They also changed color to black instead of a blue/black mix. This is good.
I’m now able to play a game of Super Pacman except the vertical bars get in the way. After seeing the board POST yesterday, I pretty much settled on this being a power supply issue. I disconnected the power supply PCB and began to examine it up close. I noticed this right away:
Here’s a view from the underside:
I have a few options at this point…
1. Replace the component on the board and continue troubleshooting it.
2. Take the board to ABL Electronics and let them diagnose and test it for a fee.
3. Eliminate the original linear power supply and replace it with a switching power supply.
I plan to get an estimate from ABL Electronics and read up more on swapping this board for a switching power supply. I’ve already come across a few troubleshooting web pages that insist the black bars are caused by grounding problems inherent to this type of linear power supply.