Adapter HP PA-1121-42HN 18,5V 6,5A

[Fabbrone]

Good morning at all, I tried to open it and visually see two R0.1 1W resistors that are broken interrupted and are positioned between a MOSFET 2SK3934 and ground.
Does anyone have any idea?
In case I have the scheme.
Thank you

[eccerr0r]

Re: Adapter HP PA-1121-42HN 18,5V 6,5A

These are probably current sense resistors on the primary side. Likely the MOSFET and other parts are also fried if these resistors are fried...

Pictures are always great.

[momaka]

Re: Adapter HP PA-1121-42HN 18,5V 6,5A

These are probably current sense resistors on the primary side. Likely the MOSFET and other parts are also fried if these resistors are fried...

I concur.

Typically, you will also find the input fuse blown, though sometimes the NTC thermistor can go down instead.

[Fabbrone]

Re: Adapter HP PA-1121-42HN 18,5V 6,5A

I attach the photos, testing the resistivity on the MOSFET pins is always from 20 to 25 ohm also by inverting the tips.

[momaka]

Re: Adapter HP PA-1121-42HN 18,5V 6,5A

MOSFET is probably bad then. Remove from power supply and re-test, although I suspect that would be in vain (but it is never a bad idea to double-check parts).

Might also want to check the snubber circuit too, after that. The snubber typically consists of a cap and resistor in parallel together in series with a diode.