Has anyone ever overclocked a Genesis 2 Rev 2.3?

Hello folks

Trying to do myself up a nice VA2.3 Genesis 2 (single switch region, dual colour LED blue-PAL, red-USA, purple-JPN, colour fix and audio fix).

Having trouble with the overclock, lifted pin 15 and all I get is garbled graphics (using 4 pin 10.0Mhz oscillator). The original trace also continues to the YM2612 sound chip. If I connect that to 10Mhz as well the sound will of course be off as well.

I have overclocked model 1's (VA4, VA5/6's) and model 2's (VA0, VA1.8 and VA3) with success, so it seems odd that this one is out.

In case it was an oddity I have 2 VA2.3 boards and I tried it on both.