Yeah, definitely a voltage problem. I would add the 12 ohm resistor mod as stated on Pinwiki for the LM323k to bring up the voltage to ~5.05v. The 24 ohm resistor would only bring it up to ~4.93v. I had did this on several games I had intermittent issues with resetting once a month (that were about 4.9v) and they are working well since bringing them above 5v. Even these games did perfect under a huge load at the Houston Arcade Expo for 2 full days without any resets there.

The threshold seems to be anything 4.85v and up will be enough to boot up the game. 4.8v to 4.84v will definitely have reset issues if you happen to get it to boot up and start playing a game. I had been through that with another WPC game that I have but since has been working perfectly since adding the resistor mod.

As Pinwiki mentions, the LM323K is actually an adjustable regulator, which the resistor mod will be needed to adjust it.

Once I had a driver board putting out 4.9v, but after installing a new LM323k, it actually dropped down to 4.84v and started resetting often. I even read that the part had changed over the years and the reason the resistor mod is now needed because of this.

You'll definitely want to install a 24 ohm 1/2 watt to raise it to ~5.05v. TTL circuits will be able to handle up to 5.25v, so this will work out well.

I see no relationship with resets and J115. Just focus on raising the 5 volts.

That is not how Pinwiki shows how to do it. In the case of removing C9, I don't think you can get around not cutting that trace at C9. Also the Metal case has to be isolated as well with the other trace that needs to be cut.

Procedure:
1.Isolate the LM323K's metal case from board ground by cutting the ground traces that run left and right from the nut on the back of the board that bolts the LM323K to the board. The neater you make these cuts, the easier it to reverse this hack.
2.Some versions of the Power/Driver board include a ground trace on the component side of the board that provides a ground to the tantalum capacitor at C9. This trace must be cut on the component side of the board.
3.Add a 1/2W resistor in series, from the LM323K ground to the board's ground trace.

http://www.pinwiki.com/wiki/index.php?title=File:LM323KHackSolderSide.jpg

Any tarnished pins on J101? J115 still does not have a logical relationship. What type of mods do you have in the game?

Also reseat the 2 molex connectors at out backside (output) of the transformer. Also look for tarnished/burnt pins.

Can you install the original LM323k back into the board? I had to do this once before as new ones are sometimes much lower than the original parts.

Awesome. As I mentioned, one new LM323k did not work for me either, even with the resistor mod. I am not sure where I had purchased mine from.

Pinwiki suggests not to replace the part unless the voltage is 4.7 volts because the new ones are made different these days.

One more thing, if the 5v ever is above 5.25 volts, you also could have intermittent boot up, and lowering the resistor to 12 ohms may be necessary.