Well, no luck trying with the resistor. But I also think I might have a bad power supply.
Once I get a new one in I'll post an update. It'll probably be two weeks
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My Arcade stuff
OK, so after lots of playing around, I've learned that de-suiciding was actually working even before using that 75 ohm resistor.
The issue was the faulty A board. It would only boot once out of every 10 or so tries of power cycling. Holds true even with the phoenix roms I tried.
Got a new A board and everything is fine. Thanks again everyone for the help and suggestions!
Sorry for the thread necromancy but I'm having very similar issues.
Does anyone know what voltage at the chip is required to program? I've bumped my power supply up a little but the DL chip voltage sits at around 4.4v.
I've tried to get a forward voltage reading on the D1 zener diode but its OL each way, and resistance shows it as 10mO one direction and open the other.
Think the diode is dead, does anyone know what the zener voltage of D1 should be for a Rev 4 board?