"What kind of repair?"
Is there such a thing as a keyboard overhaul to make it good as new? I have three of these keyboards. One escape key needs to be re-soldered (I took apart the switch to see), and a couple keys on each keyboard work only 80% of the time so you have to strike them twice. I've taken them apart and de-oxit'ed them which seems to help, but then the key to the left of the one I just cleaned will stop working too. Once the keyboard has been in use for 10 minutes or so the letter keys are okay, but the space bar is intermittent (I have not tried to take it apart yet).