This is probably caused by either the processors are not seated properly or there's a a short circuit between the motherboard and chassis. Please try the following to resolve this issue:
(1) Remove the processors and carefully install one in the socket marked CPU 1 and turn on the system. If it now works, carefully install the second processor.
(2) If the above step still doesn't solve the problem, then please remove the motherboard from the chassis and try step (1) again.
(3) Measure the battery voltage using a voltmeter. Make sure that it is above 3V.
(4) If all of the above are checked and system still doesn't work, please try with different power supply.