TA12 Samsung cell phone battery charger switch power supply, with small size, light weight, and a wide range of AC voltage (AC voltage in the 100V~240V can work), fever few and so on. but its circuit design is too simple (not current short circuit protected), often for load short circuit and switching power supply burned out, symptoms for the charger light does not light, no charging voltage output.

Measured circuit, as drawings by shows. check found: 10Q, and 3Q resistance burn broken, D3 (1N4148), and D4 (1N4007), and D2 (DW9.1V), and D5 (FU107) diode all breakdown, MJE13001 transistor burst (estimated is load charging loop short-circuit caused work current increases and caused of), replaced components Shi, will MJE13001 replaced MJE13003 (power big some). 10 ω of resistance power also to take big some, Upon completion of the component replacement battery cables and the charger connected, do not insert the battery, AC power supply, if it is working properly, the battery indicator light flashing and dimming (measurement of the charging contacts on the battery holder should have voltage output). into battery indicator lights can be considered normal.

Author of the improvement of the circuit: the circuit, FU107 at the output of the rectifier output terminals strung around a 4 ω ~7 ω/1W resistance ... it can play a protective role, and also has little effect on charge circuit. Diode D4 best substitution with FR series high-frequency rectifiers D3 also.