Audio, but no video on PS2

We have a PS2 that hasn't been used in several years. It's model SCPH-70012. It was wrapped up pretty well, so I don't think it was dropped. When we turn it on, we get OK audio (ocean sounds w/ out a disk, game or background menu sounds with disc), but no video (black screen). We replaced the cable, but it didn't help. The TV works fine when we're using a separate DVD player or an HD converter box/antenna. Any other suggestions?