I have a SMPS from a Winix WAC9500 that keeps blowing the fuse. It had some obvious bulging 200 uF 200V main filter caps that were replaced with 250v ones, but that obviously didn't solve the issue.
The bridge rectifier was replaced (RS405M), the switching MOSFET was replaced (STP7NK80ZFP) and the fuse (a 2 amp slow blow fuse) is still blowing. It isn't taking anything out with it when it is blowing.
The MOSFET is controlled by a KA3842 PWM controller. Taking that out of circuit stops the fuse from blowing, so the problem isn't in the primary filtering, or the rectifier.
What the hell would cause the fuse to blow the way it did (it scorched the board) without taking another component as well. The MOSFET I took out was fine, I was just eliminating possibilities.
Thanks.
BD1 and Q1 were removed for testing, but they were fine (I still replaced anyways) thats why they are missing from the board. C32 was never populated.
The bridge rectifier was replaced (RS405M), the switching MOSFET was replaced (STP7NK80ZFP) and the fuse (a 2 amp slow blow fuse) is still blowing. It isn't taking anything out with it when it is blowing.
The MOSFET is controlled by a KA3842 PWM controller. Taking that out of circuit stops the fuse from blowing, so the problem isn't in the primary filtering, or the rectifier.
What the hell would cause the fuse to blow the way it did (it scorched the board) without taking another component as well. The MOSFET I took out was fine, I was just eliminating possibilities.
Thanks.
BD1 and Q1 were removed for testing, but they were fine (I still replaced anyways) thats why they are missing from the board. C32 was never populated.
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