Yamaha CR-2020 Meter Lamps. HELP

Hello. I need a little help. I have a Yamaha CR-2020 Receiver. It has four meter lamps. The first one on the left is very bright. The second one is burned out. The third, and fourth ones are very dim. I have been told that they are wired in series-parallel. Can anybody please tell me the voltage, and milliamps of these replacement lamps? I measured them, and they are about four millimeters thick. Thank you very much. John.