hello you all, i've met a headake problem with my mac pro 5.1 2009, it has 2x hexa 3.46ghz, and it has worked well, but after I returned from vacancies, it won't start again, I've tested with another mac pro, and find the problem is from CPU tray, but I can't understand its behavior, neither find the problem, nor solution of course, please someone help, I note the tests on old cup tray below for your exam:
1, I put the single tray with each hexa CPU, worked
2, i put another two CPU with low frequency to the same CPU tray, there were quad, worked
3, i put back both old hexa 3.46ghz, it wont start, nothing happened, the fans turn on, no start tone, no flash, no light on logicboard, the front power light on as normal
so the cpu are good, the cpu tray is good, and they worked well, why now they wont work again? not a clue, please help.
1, I put the single tray with each hexa CPU, worked
2, i put another two CPU with low frequency to the same CPU tray, there were quad, worked
3, i put back both old hexa 3.46ghz, it wont start, nothing happened, the fans turn on, no start tone, no flash, no light on logicboard, the front power light on as normal
so the cpu are good, the cpu tray is good, and they worked well, why now they wont work again? not a clue, please help.