New build no voltage

[AndrewB]

I am hoping to get some Insite into what to do next..... the situation:

I installed the (new) mini buck converter backwards. Plugged in the heater meter and it fried my pi zero. Now I am getting 0v at the plug, I have been able to get 1-3v at the 12v pin on the buck converter but no voltage anywhere else

What I have tried so far
Replaced both base board diodes
Replaced Q3
Replaced the power jack
I have another HM that the power supply works ok
My next step will be to replace the MOSFET

Any suggestions would be appreciated

Andrew

 

[GSpinelli]

Remove the buck converter from board and test standalone, perhaps it is fried.

 

[AndrewB]

Remove the buck converter from board and test standalone, perhaps it is fried.

I removed the buck converter and still had no voltage at the power plug.

I also tried removing the MOSFET and same result.

 

[GSpinelli]

You could prove around the board with a meter looking for low resistance in the 12v path, it does not hit that many locations. Since this is a new build, could be something else like a solder bridge. High quality photos always help (both sides)