I am very sorry to inform everyone on this list that I had a severe power problem with my Micro Desktop 1.7. I applied power to the DC Jack and the area right to the jack burned out. (see attached picture). One thing that I noticed today was that UART worked when the card was powered up whilst attached to USB OTG alone (DC Jack on MD not connected)! But according to the wiki this should not work at all because of the Y6280 current control IC set at 1A acting as a diode in this case. When I applied power only to the MD I noticed that UART output was complete garbage (random characters). I don't know if only sometimes or everytime. When on DC power, board in FEL-mode with no card and pressing '2', then connecting USB OTG and booting U-Boot sunxi over FEL everything worked flawlessly.
As I said I am very sorry that I screwed up. Luke, do you have any ideas what went wrong? Do you think this +also destroyed the computer card? If the error is on my side (embarassing but still the better +case) I will have to swallow the bitter pill that I screwed up badly. I am still going to cover the costs of computer card and MD so there will not be a financial loss to the project. I am very disappointed as I have made could progress. Had sunxi U-Boot, sunxi 3.4.104 kernel running and booting Debian Stretch rootfs...
On the other hand if this is a general problem better we know it now and can take the necessary steps.
Pablo
