Pin measuring is not really an method of getting good conclusion, just sometimes perhaps could point to a problem if its an evident short or something like that.
You could try taking the driver which measures the higher resistances of all, hopefully that should be ok, and try some tests with that single driver installed. Also if the driver are susceptible to draw too much, do the upload without them so they dont deplete the 5v like it was in your measurements. You will also have to try replace the 7805 with a new good one.
You could try taking the driver which measures the higher resistances of all, hopefully that should be ok, and try some tests with that single driver installed. Also if the driver are susceptible to draw too much, do the upload without them so they dont deplete the 5v like it was in your measurements. You will also have to try replace the 7805 with a new good one.