Spectrum AP-H083-substitution card active speaker switching power supply, computer says audio sound card properly with battery-powered, and when using the AC power supply is not receiving power. Carefully observe the machine power switch has 3 positions,FX6service manual download site
FX6service manual download site
Switch stationary flat position is power off, switch the left side press is on AC power state (220V AC power to the machine and battery inside the machine is broken), right side pressed the switch is inside the battery connect the power supply status.FX6service manual download site
FX6service manual download site
Take apart speaker back cover and found that the power transformer rectifier AC power supply is not used to charge the battery, but switching power supply replace power transformers. Press the power switch on the left side, measure primary switching power supply filtering capacitors μ F/400V ends for some 68 290V voltage, DC negative terminal of the diode not voltage;FX6service manual download site
FX6service manual download site
Power outages, measured the load circuit is not short circuit; welding rectifier diode open at one end, measure the forward and reverse resistance to normal, indicating points of failure in the primary switching power supply circuit. Observe the structure of switching power supply, use a lot of SMD transistor, diode and micro-chip, is more difficult to have a thorough analysis of the working principle of communicating with the owner decided to use normal power supply after switching power supply transformer substitution.FX6service manual download site
FX6service manual download site
By: 220V power switch cable from SMPs input welding down the retrofitted transformer 220V input, transformer selection wide 19mm, folding 38. El iron cores, transformer secondary 13.5V after two 1N5408 2200 μg F/25V full-wave rectifier, a capacitor filter, get no-load voltage of 17V DC, negative switching power supply of the secondary filter capacitor cathode, secondary filter capacitor cathode cathode switching power supply. Refit completed power test AC power supply card is working properly, troubleshooting.FX6service manual download site