Just to rule out the power adapter, you could try a laptop AC adapter. In most cases, those have a 19V adapter, and I can tell you from personal experience, the Form 1/1+ will power up with it.
I'm not saying you should print with it, but at least you'll know if the issue is with the power adapter, or internal with the printer.
Once you plug in the PSU, turn on the printer. If the logo shows up, then problem is with you adapter.