[Les]

Sorry to say it, but the only solution is to replace the sockets in the ten lights that have failed. Then put brand new lamps in them. Do not put the old lamps in lights with new sockets or other instruments with still working sockets, because the pins are likely to have been damaged by arcing. Which will in turn ruin any lamp base you put them back into. For around $20-25. a piece you can get these from any theatre supplier. I believe you are looking for a TP22 socket, which is a common part. Others can tell you more as far as replacement cost and details go. Good luck!