Need help troubleshooting Power Supply or Logic Board issue on 2017 iMac 21.5

[Zataralos]

Hoping to get some guidance as I can't find any schematics for my iMac . I recently changed the EFI chip on a 2017 21.5 4K iMac and now it won't boot. LED1 comes on and LED2 flashes every 5 seconds but power button does nothing. I checked voltage at the power button and getting 3.28v. Trying to figure out if it's the PS or the logic board. I took a few readings while it was plugged in (see attached photos). What else can I check before starting to replace parts. In case you're wondering, yes I know how to micro-solder and installed the EFI correctly

Any help, especially on what voltages I should be seeing in the power connectors would be great.

Thanks

[fzabkar]

Have you looked here?

https://boards.rossmanngroup.com/forums/macbook-logic-board-repair-questions.15/