This sounds like a very common problem. If the blinks are one short, one longer, one short..... long pause... repeat.... start searching this forum. There are also Youtube videos on solving it. If this is the problem, the solution is easy. You block both center pins on the 10 pin power connector. Its crazy but it works.
I just used a very thin strip of paper folded in half and slipped into the display's connector so it covers ONLY the two center contacts, then slip it into the power module very carefully. Make sure there is some slack in the paper as otherwise it will tear and the contact will still be made. If it doesn't work at first, try again as the paper made have torn in process. It would be better to use something stonger like a very thin strip of mylar. Or you can do what the video shows, but I didn't try that exactly.