hello
am an avid reader of your articles.this is great micro soldering.Apart from Alibaba,where else can we source for micro components,spares and tools and what are common universal smd components to stock.thanks

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Testing Mosfets is easy but at best can be only done off board. On board we only can measure if they are short circuiting or having a wrong resistance which tells us that they must be defect. By using your DMM in diode test you can switch any of the in the article used mosfets in on state or deactivate them to open switches. Gate is mostly pin 4 (in a single Mosfet). pin 1 to 3 are Source and 5 to 8 are the Drain pins. And if you place your Multimeter red and black input probes on pins 4 and any of the source pins you can change the condition the Mosfet is in by switching the black and red DMM probes. If it conducts (is activated) source and drain are connected. And if the mosfet always conducts or is short circuiting between Gate and Source or never acts as a 'digital' switch, you know it is a bad one and must be replaced.

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Excelente reparation. Could you explain how test both MOSFET? When you said:

"And with our DMM we measured about 450 ohm over both mosfets. "

What pins do you measured? Do you measure the MOSFET out of PCB?

Thanks

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