Nikon SB-800 speedlight to be repaired?

After eight years using it quite a lot, my SB-800 stopped working today. It can be switched on, but it doesn't flash any light from the lamp neither shooting it on the camera nor pushing the test button.

Using it with a D800, is it worth to change it for the newest model, the SB-910 ? Keep in mind that it's been used from 2004...Is it a long time for a speedlight, or maybe not?

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