The electronics PCB is the main section of the baton. There are several different versions. These can be divided into two main catagorys. The small board with wires and the larger board with led integrated. Functionality is very similar except you cannot replace a large board unit with a small board but you can use the large board unit in most casings.
Some older boards were encased in epoxy. If this is the case it is very difficult and costly to do board level repairs under the epoxy. The procedure to repair a fault under the epoxy requires you to take a small saw and carefully remove the epoxy before following normal procedures to carry out the repair. Bigger boards encased in epoxy can get a fault where the heavy epoxy lifts from the board due to multiple concussions. This normally also lifts electronics from the board at the same time.
Some boards have jumper pins or switches to manage the power. If the unit has a switch or jumper it is recommended to replace it with a wire. Jumper units might already be damaged if the jumper was soldered together. This might require you to solder a wire to an extra place on the board as shown in the picture.
The values and part numbers indicated below are for the 2010-2013 boards. This might be different for other boards. Any of these components can have an intermittent fault or a permanent fault if the board is twisted. Twisting the board sometime results in excessive stresses in the components and they lift. excessive heat and cold can also cause this.None of these components have a specific orientation and can be ploaced any way around.
R2 is a 1k resistor used to protect the board from high voltage.
R4 is a 1k resistor used to supply current to the led.
R6 is a 100R sacrificial component which will be blown to protect the board from prolonged high voltage.
The inductor is also a protection component.
The unit should not draw more than 5uA. There can be several reason for this fault.
The clock chip and crystal are used to keep accurate time on the device. The crystal can be damaged by excessive force which normally results in a clock stopped condition. The clock chip can also be damaged by board twisting or electrocution.
The data chip is used to store all data clocked in the system. The data pointer for where data is stored in memory is kept in the microprocessors. If the unit is electrocuted this can result in an undertumined data pointer which results in corrupt data.
The LED is used to indicate a proper point clocked. This can be physically damaged or electrocuted. This does need to be placed the correct way around when replaced.
When physical damage is involved, tracks can be removed or damaged. This can be replaced by wire if the copper is cleaned from the ends of the tracks and the wire soldered to it.