My printer now runs again! This is quite embarrassing.
Here's what I did: Scrapped the old USB-cable got a new one. Switched power jumper to USB. Got connection in Pronterface, led flashed happily. Noticed that ground cable in 12 V supply socket was actually a bit loose/moveable. Remounted it firmly. Switchet power jumper to PSU. Printer worked perfectly.
Lession learned: Pay attention to mounting of power cables from PSU onto the Melzi!
I already knew bad power connection is a usual cause for this dramatic incidents, I don't understand how I could miss this myself for so long... Hope this is my last stupid mistake. Haha.
You were right, Cefiar. Ground difference between board and USB was really the problem. Thanks again! :)
Best regards
:)-D
Here's what I did: Scrapped the old USB-cable got a new one. Switched power jumper to USB. Got connection in Pronterface, led flashed happily. Noticed that ground cable in 12 V supply socket was actually a bit loose/moveable. Remounted it firmly. Switchet power jumper to PSU. Printer worked perfectly.
Lession learned: Pay attention to mounting of power cables from PSU onto the Melzi!
I already knew bad power connection is a usual cause for this dramatic incidents, I don't understand how I could miss this myself for so long... Hope this is my last stupid mistake. Haha.
You were right, Cefiar. Ground difference between board and USB was really the problem. Thanks again! :)
Best regards
:)-D