im assuming the 880 is pretty similar to the v890, which we have. I just did the same thing not too long ago, and all went fine. honestly, the only thing I can suggest is when putting the cpu board back into the system. Be careful that it is aligned and strait before you make connection with the backplane. We had an issue another time where some memory went bad, it was under warranty, so Sun came out and fixed it. long story short, the person who came out to replace the memory, kept putting the cpu board in at an angle which messed up the pins on the backplane, once the pins are messed up, there is a good possibility that the system board has to be replaced as in our case. I don't think he was forcing it in at an angle, but just enough to mess it up. So we requested another person do the work, and after the system board was replaced, and cpu board inserted, the system came up fine.