The filament of a 40W bulb snapped when I touched the metal body of the lamp. It's safe because it has an OS 800 touch switch similar to this one. Schematic is here.

When I opened the switch case, I noticed the triac BT131 burn up. I replace it by mistake with MCR100-8 T/B thyristor. At the terminals of the thyristor there is a 220 V sinusoidal signal.

The lamp with a new bulb does not work. I measured on oscilloscope the signal at thyristor gate and I think there were 50 Hz pulses about 6.2 Volts with a slightly blurred, multiple edge to the right. No change when I touched the lamp. There is a jagged sinusoidal signal on diode D3 1N4407 +- 40 V.

I think the IC TT6061A burn out too without any noticeable damage. What's your thought. Is there any new IC circuit which required less external parts?

P.S. I am a certified electrical engineer who can work under mains voltage.

 

Three possible explanations appear: First, the replacement device is not getting an adequate drive command, second, the replacement device connections are different, and third, some other component was also damaged when the bulb failed. That is a real possiblity