It's been a while since I have soldered, so I bought a [cheap unbranded soldering iron][1] to use while I re-familiarised myself with the skill. After a few weeks of use, I turned it on just now and it popped with a blue spark. Now it appears to be dead. Did I do something wrong, or is that simply what happens sometimes when you buy a cheap soldering iron? I'm curious to find out what could have happened.

Ironically, I actually bought a new soldering station (Hakko FX-888D) earlier today, not sure why, just had a feeling it was time to get better equipment... spooky.

Out of curiosity, I dismantled the dead soldering iron and took a photo of the board inside.

[![Dead soldering iron PCB][2]][2]

With my limited knowledge of electronics, my intuition tells me that an arc occurred between the AC wires. If so, is this bad luck, bad soldering, or user error? 

[![Close up of the burnt AC wires][3]][3]

The insulation appears burned, but also the core of the wires seems to be a bit frayed. Was this as a result of the arc, or low quality manufacturing?

*Bonus question:* I wasn't touching the button at the time the iron popped, but if I was, would I have received an electric shock? Would it have been life threatening or painful?

  [1]: https://www.ebay.co.uk/itm/203450194573
  [2]: https://i.sstatic.net/JHrz8.jpg
  [3]: https://i.sstatic.net/aKqa0.jpg