1, will be repaired to open the jukebox, using a multimeter to measure the voltage of the positive and negative battery pack, the normal value should be 7.4V, but the measured battery voltage of 6.2V, at this time the pen does not move will be a host of chargers to observe the multimeter readings are still so there is no change in this phenomenon indicates that the charger is bad or the charging circuit has a malfunction.
2, first with a multimeter to measure the charger output voltage of 10V, indicating that the charger is normal no problem.
3, the charger host, using a multimeter to measure the voltage of the charging circuit, and along the circuit towards the measurement, found in the two current-limiting resistor end of the loss of voltage.
4, with a multimeter to measure the charging circuit components in the road resistance, when measured to the two chip current-limiting resistors, found that the resistance value is not normal.
5. Remove the two resistors and replace them with chip resistors of the same resistance value.
6. After replacing the two R100 chip resistors with brand new ones, the battery voltage was measured at 6.2V, and then the charger, at which time the multimeter readings immediately rose to 7.1V, indicating that the charging circuitry has been restored to its normal state.