I'm trying to flash my device from the 34xx firmware to the 37xx firmware (I have a 3790). I followed the guide exactly and used Updater to flash back the 37xx_450.rgn firmware. It was stuck at 100% and then gave me a program error. Now when I turn on my device, it only has no display but there is still backlight. I'm trying to flash it again but cannot put in pre-boot mode, I already tried pressing over the upper left OR above the G (I cannot see the Garmin logo here, so I'm just estimating) but the PC cannot detect it in pre-boot mode.

What can I do?