You're going to want to open it up before you turn it on ideally. Like Bubo said, there are likely battery leaks and you want to clean those up ASAP to prevent further damage to the motherboard. If you can, do a recap beacuse all t he old capacitors used tend to be a bit rubbish by today's standards. The chips on the other hand are beaautiful! You're also going to need an old CRT/TFT that can do 15khz mode for the output OR a scan doubler to get it working with something more modern. There are lots of option there though.