Connectors on SB900 flashlight?

I have a nikon sb900 speed/flash light. Seems like the connectors are faulty or worn out. Can you just replace the connectors or hotshoe? Can you do it yourself?

Probably if you can find someone who will sell spares and a service manual. The flash will have a dangerous capacitor inside capable of giving a bad shock, be very careful when opening the unit.

Personally I would hesitate before opening an expensive flashgun and look what service is available commercially.

Does the flash work on another camera, it may not be the flash, or something may be in the wrong mode either on the camera or flash

Anything can be fixed with the knowledge and skills to do it correctly. But most people do not posses these skills and will only make it worse.

And heed the advice above. There's a big capacitor in those flash units that can bite you if you go tearing the flash apart without any idea of what you are doing.