Hi Mitch, indeed there are possible issues when upgrading firmwares on the Form 1+. You don’t need to worry about upgrading your firmware, PreForm will notify you if the Form 1/Form 1+ firmware needs to be updated.
I am going to go into a bit more technical depth to explain what is going on, and why this part of the process has always been a bit dodgy.
When upgrading the firmware on the Form 1+, the printer temporarily gets switched to a “DFU” mode, which means it now accepts the new firmware and reprograms itself. Because memory is very limited during that time, the screen stays black, which can be quite confusing. When it switches modes, it also gets recognized as a new USB device, which can lead to driver installs and other issues from the operating system, resulting in a timeout. One possibility here is to just unplug/replug the USB, possibly into a different USB plug. At this point, PreForm will see a printer in DFU mode, and immediately switch to the firmware upgrade.
Now the “worst” case scenario is if you started a firmware upgrade, and pulled the plug midway. Now the printer cannot leave DFU mode, since the main software has been partially overwritten. Plugging in the printer does “nothing” as the screen stays black. Don’t panic! Just plug in USB to PreForm, which will recognize the DFU mode, and merrily update the firmware correctly.
The last dodgy part is that after the new firmware has been flashed, the printer has to reset itself to leave DFU mode. This requires the USB bus to be reset, an operation that has been a notorious moving target. Depending on the USB drivers you have, this operation might have been disabled (certain Windows drivers), or not reset the bus entirely (newer OSX), and it’s a bit of a cat-and-mouse game for us. There is, however, a very reliable USB reset method, which is unplugging the cable, and if that doesn’t help, powercycling the Form 1+. After that, your newly flashed form1+ should be recognized by PreForm just fine.