And if I don't have the AC adapter?

[BillC]

Is there a way to trigger the firmware install without the AC adapter?

I've been charging my X5 from a USB cable and have no idea where the AC adapter is anymore.

[oggb4mp3]

I thought the X5 didn't charge from the USB.  How are you doing that?

[Hweb21]

i think he has been charging through the cowon firmware not rockbox.

[xlarge]

Is there a way to trigger the firmware install without the AC adapter?

I've been charging my X5 from a USB cable and have no idea where the AC adapter is anymore.

No, you have to have the adapter.

[xlarge]

I thought the X5 didn't charge from the USB.  How are you doing that?

Right now you can only charge OR run rockbox (the same goes for cowons original firmware except "right now" as i'm guessing that will NEVER happen.. With rockbox there is a remote chance perhaps).
The way you charge with the usb-cable is connecting it and then long-'pressing' power, cowons disk mode will change to charge mode.