After the another WTF is wrong with my board/code/brain I decided to put together a rather compact database of abnormal behavior of those semiconductor pieces of… ICs

Analog ICs

MIC5504 voltage regulator: Huge current consumption in the disable/bypass mode

In the Lego Elevator project I have used 1.8V initially, but some LEDs just look better with a larger voltage drop. And, since, it is a toy I wanted them to look better obviously:

I’ve placed a header for a bypass, so I thought putting EN to GND will allow me bypass the voltage without issues and it did, though the current consumption was almost 70mA without any consumer on the PCB. Removing the IC regulator from the pcb resolved the problem.

Microcontrollers

PIC16F18046: RA2 button acts as MCLR

Confirmed by the debug and monitoring registers with SNAP Microchip tool. Had to completely drop usage of this button since it was not possible to use it at all.