Yes, on the 4011.
Hang on, the LED pulses? What, normally, at the start of every bar, so it's pulsing all the time you've got the drum machine running and stops when you hit stop?
I'm not sure how that would happen. The LED is driven by Q13 and Q14. Now R96 pulls up the base of Q13, turning the LED on all the time. When Q14 has its base turned on, it clamps Q13's base to ground turning the LED off.
So how do we get it to flash at the start of every bar? Pin 10 of the 4011 goes low during a "step". This feeds through R73 and R74 to the base of Q14. The outputs of the address counter are also fed there through R69-R72. So, if any of those inputs is high, Q14 is turned on and turns off the LED. Only when the clock is low during a "step" and we're at the first step are all the inputs off. It's a crude 4-input NOR gate ;-)
If the LED flashes normally - one little blink at the start of every bar, the counter *must* be running. The thing is, CE2 is wired to the same clock output that clocks the counter and drives the hihat 16ths - follow the trace around from the REC/PLAY switch. If the clock is working, it's in play mode and the hihats are set to 16ths, you should hear that even if the memory and counter are hosed. As a quick check, you could tack a wire from pin 11 of the 4011 to the wiper of the hihat switch and leave it switched OFF, just to discount dodgy switch contacts.
HTH,
Gordon