I have never had this problem before. Its a System 4. When testing with Leons and Andres Test for 2J5, I hook 2J4 up to 5V. The test ROM works great, but as soon as I do this, I get a short and the CPU locks up.

I have tested the transistors and they all seem good and read the same. I tested IC13 and IC14 (they are the 7408). When the chips are pulsed, the blanking signal at the pins is 4V, the signal at the other AND pin is 3V, and the output shown is 1.5V.

I cant find anything wrong! If I attempt to hook 2J4 to the 5V, it locks. Any ideas!?

This has always worked in the past. That is odd. Did you mean the 7408 or the 7406?

I have pulled a few of the transistors out,and it is actually working now. My power supply hasnt ever had an issue.

Ok, I plugged it into the game and none of the controlled lighting is working. I replaced the 7408, as I mentioned. I wonder if the 7406 or PIA is bad and making too many of the transistors power on? I think the PIA tested good, if I recall. I will replace the 7406 and get back.