SH-101 External LFO clock input

[media at mail1.nai.net]

I'm trying to and an external clock input to the LFO of an SH-101 so that I
can sync the LFO and arpeggiator to the same external clock.

I know people on this list have done this.  Does this list have searchable
archives??  I'm trying to install this mod from a diagram I downloaded from
the web over a year ago.  Unfortunately it isn't a very good diagram, it's
quite vague, and it's not a schematic.

Basically, from what I can tell, this mod takes the input of pins 2 & 3 of
IC3 (the inputs to an op-amp) and replaces them with the tip and sleeve of
the incoming clock using a double-pole switched jack.  The diagram says to
unsolder the entire IC, bend back pins 2 & 3, and then resolder the IC.
That sounds nuts, and remember someone burning their IC attempting to do
the same mod, so I achieved the same circuit by cutting traces instead.

Anyway, breaking the connection between pin 3 and the preceding circuitry
kills the SH-101 -- the front panel lights display contradictory messages
and the unit makes no sound.  Grounding pin 3 seems to make no difference.
The Roland service notes do not show where pin 3 of IC3 goes -- the
schematics show it going to a dot with a line through it.  What does that
mean??  Tracing the connection from pin 3, it seems to go to pin 1 of IC1
(M5218L, which according to the service notes seems to be a dual op-amp in
a single-inline-package, no pin-out is shown).

I no longer have a scope, but the inputs of the IC3 op-amp seem to be held
at around 5V, so I'm thinking the unmodified input is a short negative
going pulse.  If I reconnect pin 3, disconnecting pin 2 from the rest of
the circuit and momentarily bringing pin 2 to ground seems to advance the
clock, but it is also erratic.

Any idea what I could be doing wrong??

THANX!!