You have 3 surface pro's and all stopped charging and went to sleep mode. This happens to me as well but only for single device not for all. Actually this also happens to me because of the issues in extension board. You should also check that one.
Every electronics is repairable by the manufacturer as they have the right tools to work with. So, in such condition when our system or any other electronics product is in warranty period then we should send the product to manufacturer service station.