I'm a total beginner when it comes to soldering, and recently I've been trying (and failing) to solder together a simple circuit I put together for a Raspberry Pi sensor.

[<img src="https://i.sstatic.net/B75uX.jpg" width="300" alt="circuit on a breadboard" />][1]

Although it works fine on the breadboard, when I solder it onto one of my perfboards, the sensor no longer turns on.

[<img src="https://i.sstatic.net/KT5K2.jpg" width="300" alt="circuit on a perfboard" />][2]

Here is a topdown view of my soldered circuit

[<img src="https://i.sstatic.net/iCkry.jpg" width="300" alt="Connections" />][3]

Here is a view of the connections(the red block is just covering up old connections from past attempts)

[<img src="https://i.sstatic.net/UbThX.jpg" width="300" alt="Connections" />][4]

More pics of the connections

Can anyone tell me what I might be doing wrong? Any advice for a noob like me?

  [1]: https://i.sstatic.net/B75uX.jpg
  [3]: https://i.sstatic.net/iCkry.jpg
  [4]: https://i.sstatic.net/UbThX.jpg
  [2]: https://i.sstatic.net/KT5K2.jpg