I will be putting 1k ohms resistors in series between the Ramps signal pins and the DQ860MA tonight. I'm also going to replace the suspected "burnt" optoisolator FairChild HCPL2531 with some scavenged EL817 EverLight on the DQ860MA driver.
hopefully this works for testing until exact matching optoisolators come in...
hopefully this works for testing until exact matching optoisolators come in...