====== 206.204.62 KORTLINJE ======

<blockquote>Alarm clock with hygro-/thermometer, red, 18x6x7 cm</blockquote>

===== Disassembly =====

  - Battery cover
    - Loosen 2× M2×7 captive screws
    - Remove the part
  - Battery holder and rear button plate
    - Remove 5× ST1.7×6 screws
    - Lift up the part
    - Insert a long screwdriver e.g. a test pen to push on one of the retaining tabs on the rear plate
    - Pull upwards on the corner to free it (do not pull too hard to avoid breaking the other tab that is still engaged)
    - Push on the remaining retaining tab while pulling upwards to free it too (be careful not to re-latch the other tab)
    - Remove the part
  - Power board
    - Remove 4× ST1.7×6 screws
    - Lift up the part and flip it over to the bottom side of the board to free it
    - The part cannot be removed fully as the wires are soldered on both ends
  - Mid-frame
    - De-route the power cord from the cord grip
    - Remove 6× ST1.7×6 screws
    - Remove the part
  - Main board
    - Remove 8× ST1.7×6 screws
    - Lift up the part and free it
    - The part cannot be removed fully as various wires are soldered on both ends

===== Main Components =====

  * U6 is an unmarked IC (SOIC-16N package) and likely an 8-bit MCU running the show
    * Pin 3 ↔ VPP testpoint
    * Pin 4 ↔ CLK testpoint
    * Pin 7 ↔ GND
    * Pin 11 ↔ SDA
    * Pin 12 ↔ SCK
    * Pin 14 ↔ Buzzer
  * U1, U2, U4 are VINKA VK1640 (SOP28 package) LED drivers
  * U3 is an unmarked IC (TSSOP-24) and likely an RTC
    * Pin 2 ↔ GND
    * Pin 14 ↔ CK testpoint
    * Pin 15 ↔ 32.768 kHz crystal
    * Pin 16 ↔ 32.768 kHz crystal
    * Pin 23 ↔ V
  * Photodiode for automatic brightness
  * Sensors in the clock leg with a vent
    * Analog humidity sensor
    * Analog thermistor
    * Buzzer on this external sensor PCB