I found the 18k resistor labeled R15. Its connected to a diode at the top where the shadow covers detail. I follow the diode to the 1K resistor. Another 1k resistor, cap... Then... I'm lost.
I hate to say this, but I need to hold off for a week or so. I've neglected my domestic tidiness and my girlfriend is hosting foreign friends this coming weekend... I'll definitely be back at it and hope to have some result. Good or bad, whatever it may be.