As you know i am rebuilding a plane. So i gutted it out and found out that the receiver is a kyosho PCM 5 series 91. It looks okay and has the crystals but how can i test it to see if it is okay. Also the battery is a Sanyo 4.8v nimh 600mah battery and has been sitting for 20 years so i know it's bad. So where can i get a lipo battery that will work?