@rodcastler: I did not dare to open the case to make a photo due to the flying composition. Since the hack, it still works fine after 4 years.
You can identify the heating regulator's output easily with Dave's video or by following the connections of the original LED. Then have a look at the signal using your oscilloscope.
If you see PWM signal, it's a microcontroller. Otherwize, if the LED receives a constant voltage level while it is on, you got the opamp version, like I did.