As c_mario stated, if you haven't changed all the connectors, you're throwing darts. Change everything from the two red wires on the transformer connector up to the driver board, and then the connector from the driver board to the CPU. Change the header pins too, on the driver board (AC in and DC out) and the CPU. 9 out of 10 times this takes care of resets.

I've fixed resets on games that were using the Kahr reset boards. The Kahr board worked for a while, then resets started again. Why? Because the connectors and header pins were the actual problem. The Kahr board is fine if your issue is caps, bridge, or the regulator. They aren't a good solution if the problem is connectors. And since the problem is usually the connectors...