In this post we are going to look at the insides of a GPS signal block from Aliepxress. The product listed a few specifications about the device, those can been seen below.
The circuit board is housed inside a plastic clamp shell and doesn’t have a whole lot on the board.
The display on the device is a fixed LCD panel with a light diffuser behind it. Although it shows numbers and text this is always the same and the electronics have no way of changing the display text.
On the rear of the board there are two SOIC-8 ICs and a voltage controlled oscillator (VCO). After a lot of searching I could not find the part number for the VCO.
The IC directly next to the VCO is a 555 timer in a SOIC-8 package. The IC below the 555 timer does not have any markings. The mystery IC is is connected to the LCD display.