I bought another soldering iron, very expensive to me. I am very exciting about it. Upon receiving it, My heart is broken. First, I saw the label, 220V; Our AC voltage is 110V. Tried it, doesn't work. Not even heating up.
With a heavy heart, I disassembled it, trying to fix it. Great news, the heating element is measured 62 ohm, so It should work with 110v. I have tried to change 40K to 20K, and 1K to 500, but it doesn't work.
Here is the schematic that I got from tracing the PCB. There is a MCU supposedly used to controlling the duration of the triacs, thus giving it a variable temperature. Also, it's a 120W soldering iron. For me, I can live with fixed power @ 60W. what should I do here? I am not very familiar with AC circuit.