I deconstructed a toy firetruck that lights up and makes noise.
I first decided to take out the batteries in the bottom so that it wouldn’t be going off if the ladder hit one of the three buttons.
It ran on two 1.5 volts button-cell batteries. After the batteries were removed, I unscrewed the five screws that were holding the case together. One of them refused to come out and appears that it wasn’t screwed in to begin with. When I opened the casing it revealed the wiring of the circuit.
I decided to remove the board, from the casing, so as to allow more flexibility in the positioning of the two halves of the casing.
The board has two resistors on it, a 200k and a 56 ohm resistor. The black blob on the board is where the chip is at that is programmed to produce a certain reaction depending on which button is pressed. The three buttons come out when you remove the board. A majority of the wires are attached to the three LEDs that are in the front of the truck and light up. Two red wires connect to the speaker that is in the back, and one yellow and one red wire connect to the battery pack. The battery pack cannot be taken out without destroying the soldering between the wires and the pack. The speaker can be taken out by unscrewing the two screws first, and then by taking a flat head screwdriver and levering it out under the plastic ring that is around the speaker.
The LEDs are screwed in with three screws that need to be unscrewed. You must remove all of them because the LEDs are all placed into one plastic piece. It is also easier to unscrew the screws if you take the ladder off the fire truck by unscrewing the screw that is below the base of the ladder, and when the ladder is remover the casing becomes flat on the surface.
The one screw that is still in was stripped when I opened it, but I got it loosened enough to pull the plastic part off.