I have a table lamp which has a busted dimmer control. When I bought it the dimmer used to kinda work but then after a few days it worked only when the rotary knob was turned all the way high. After a while it broke completely and won;t even light up. I removed the lamp and tested it and the lamp works fine. So I decided to do a tear down and see whats inside.
I managed to trace the circuit and here it is. I hope it's correct. If it's wrong do let me know.
I did some testing with my cheap multimeter and found out the values of 2 resistors, one being 1k and the other 5k. The pot showed no resistance at all which means the pots probably the part that went bust? but the pot switch works fine in continuity test.
Kindly explain how this circuit works to me and what went wrong here? Thanks in advance.
Update: ZY 406 might be an SCR, PCR406 in TO-92 package like user " Spehro Pefhany" suggested. So I have updated the diagram with this change in symbol.