How do I power on a Chromebook with a dead power button?

I’ve got a Acer Chromebook 14 that I’m doing a screen replacement on. The power button was known to not work before the repair. The customer had simply been opening the lid to ‘turn it on’.

I disconnected the battery before doing the repair, and now I can’t get the Chromebook to power-on again when opening the lid. I’m assuming it was in sleep mode before, but disconnecting the battery did a hard shutdown.

I don’t have the charger, but I will try hooking it up to my bench PSU. Does anyone know what I could try to power this thing up?

Any help very much appreciated!