OnOff-Shim is not booting PI

I have a Paspberry PI 1 with the OnOff-SHIM attached. Soldered to the female connector which is pluged to the GPIO.
I’ve run the oneline installer.
I can power down the PI by pressing the onboard button, but once it reached PowerOff state I cannot power it back on using the shim. (On cold boot, the PI is immediately starting as soon as I connect USB to the shim.)
I don’t know exacly how it is supposed to be, but the 5V and 3.3V gpio pins staying fully powered at this poweroff state.

  • Somewere I saw that BCM4 should ground when pressing the button, but this is not happening. It stays at 3.3V.
  • BCM17 does seem to ground when the button is pressed (Voltage drops when measured between BCM17 and ground, and button is pressed). But that is the tigger for the cleanshutd deamon, so I kind of knew that.
  • I checked that I have no shorts between the pins (only the two 5V pins seems to be internally connected and the two grounds, which I think is correct)
  • When shutdown is in progress the BCM4 is beeing put into low (no voltage between BCM4 and Ground), but as soon as the PowerOff state is sucessfully reached it jumps back to 3.3V
  • The shim led does light up when pressing the button.
  • There is not difference when using the onboard button or the BTN connectors.
  • I tried the shim on another RPI2. Connecting the power to the shim it immediately boots, than I shutdown it via CLI. Than I test to repower it via the button and it fails (no software installed).

I don’t know what else can be checked or measured as I dont know what is supposed to happen at the pins.

You say Pi 1, does it have the 26 pin or 40 pin GPIO header?
Did you solder all 12 pins?

26 GPIO Pins (the rest is seperate and not soldered).

Anyway, I wrote this text comming from 6h of testing and measuring. After writing this, I just did what my dentist told me, scatch everything off. If it let go it not belongs there. Followed by one last desperate test. And what can I say, starting with the plugin of the power source the PI does behave differently, it did not power on directly waiting for the press of the button. So I tested the rest, now all seems to work fine. On shutdown the shim do power off the 3.3V pin. Exactly like I have hoped.

I kind of remember that there was something shiny I did remove from under/side_of_the_LED of the USB connector of the shim. This must have briged something.

Thanks for reading and support.

Ok, so you have it working now, well done. The shiny bit might have been a stray drop of solder off of your iron. It happens some times, you just have to give things that one last good look over before plugging in the power.