QuoteJohnW Having just been through this NIGHTMARE, I can guess what is wrong with it... Assuming your board came from ebay as part of the £147 i3 kit, and was preconfigured with max and min end stops in the firmware and only min end stops in the kit... I believe you have just described solution to the problem I had for several months now. Indeed I bought Geetech Prusa i3 Pro B from ebay and itby linas.p - Prusa i3 and variants