Hi
When I switched ON this mixer, it was totally dead (No power supply). It uses a SMPS. I opened up and checked all the components. There are 2 IRFP460A switching transistors, a IR2153 Driver,2 optocouplers, 5 smd and 2 normal transistors. All the smd resistors tested OK. The electrolytic caps, diodes are also OK. This item operates from 220V AC to 240V AC. When I connect the mixer thru a autotransformer and reduce the mains voltage to around 200V AC, the mixer turns ON and operates normally. When I turn up the voltage to approx 225V approx, the power supply turns OFF. I tried switching ON and OFF, but doesn't work. After turning down the Voltage back to approx 200V and wait for 2 to 3 mins, then when I switch it ON, it functions again as normal.
I replaced the Driver IC (IR 2153) but no difference. It is written at the back that this unit operates from 220V to 240V. Can I placed some high ohm and high watt resistors to bring down the AC voltage to approx 200V AC. Please assist.
Thanks
Carlos
When I switched ON this mixer, it was totally dead (No power supply). It uses a SMPS. I opened up and checked all the components. There are 2 IRFP460A switching transistors, a IR2153 Driver,2 optocouplers, 5 smd and 2 normal transistors. All the smd resistors tested OK. The electrolytic caps, diodes are also OK. This item operates from 220V AC to 240V AC. When I connect the mixer thru a autotransformer and reduce the mains voltage to around 200V AC, the mixer turns ON and operates normally. When I turn up the voltage to approx 225V approx, the power supply turns OFF. I tried switching ON and OFF, but doesn't work. After turning down the Voltage back to approx 200V and wait for 2 to 3 mins, then when I switch it ON, it functions again as normal.
I replaced the Driver IC (IR 2153) but no difference. It is written at the back that this unit operates from 220V to 240V. Can I placed some high ohm and high watt resistors to bring down the AC voltage to approx 200V AC. Please assist.
Thanks
Carlos
There is only 1 driver IC on the board(IR2153). I am not sure whether it is driving the power amp or power supply. The Hi and Lo outputs of the driver are connected to the 2 IRFP460A mosfets. I realise that the primary of the switching transformer is connected across these 2 mosfets, which made me conclude that the IC and 2 mosfets are actually driving the power supply. All the resistors (both smd and normal) read within range. The 4 smd and 2 normal transistor test OK. There are no inductors or coils.
Carlos
Carlos
Carlos
Carlos
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