T5500 power boot up and shut down after few seconds when riser board connected

이재웅 Do you have the 8GB sticks in slots 1,2, and 3 of the mainboard? If so then it's the correct configuration for that kind of setup. If that's it then have you tried reseating both the Ram and CPU on the riser? Failing that swapping the CPUs and see if the other x5690 will boot off the motherboard.

이재웅 Also make sure the CPU/Riser power cable is firmly connected to the riser as well. From my own personal experience the T5500 reboots can happen if the Riser isn't seated correctly on the motherboard (sometimes pulling out and back in fixes this) also the power cable should be firmly in place. The other is the reseating of both RAM and CPU. The CPU swap was suggested because sometimes even a bad CPU or bent pins in the CPU socket will give off the same effect.

이재웅 Have you checked out this install video?  https://youtu.be/GYp4HepWp40

Otherwise, I do like stormson weathers troubleshooting ideas.

이재웅 it’s plug and play.  Did you make sure to install matching step codes?  Do all of the memory modules match?

이재웅 Your Intel CPU stepcodes must match.  What model cpu's do you have installed?

이재웅 Hi JW,

what @jbigticket23 was referring to was the 4 to 5 character code on each of the CPUs. Think of it as a serial number. It's usually under the model number. That code must match on both CPUs since Intel makes different variations of the cpu with the same model number.