I had a similar issue. I purchased a colorDMD for my Spider-Man (2007, Stern) and moved the original DMD to a Williams T2, which had a DMD on it's last legs. No problem - worked perfectly. After doing something incredibly stupid, I hosed a chip on the colorDMD. Since there were other issues resulting from my moronic maneuver, I needed a temporary display for troubleshooting the Spider-Man pin and attempted to use the DMD from T2...and discovered that it didn't work...only got one or two lines. I don't recall the voltage measurements, but the manufacturers were different. Pins are all operational now, but the test was surprising since I had been under the impression that DMD's were all interchangeable.