ipod shuffle 4gen wont charge/turn on, recognized by itunes

If the light on the shuffle is solid orange, it means currently charging but OK to disconnect. NOTE: If it is blinking orange, it means DO NOT DISCONNECT (because the shuffle's disk is mounted by the system); eject iPod before disconnecting. It will do this when connected if the shuffle is set to load songs manually (not automatically).

Since it is solid orange, you should leave connected a while longer to see if it becomes solid green (Fully charged - OK to disconnect). If it seems to be taking too long, and you happen to have a USB power adapter (like the one that comes with iPhone and other devices), connect shuffle's docking cable to it and connect shuffle. Light should be solid orange until it becomes solid green. Does it charge that way?

My older shuffle does that sometimes (not always). It's likely because the battery is becoming worn out due to usage and/or age. However, when I use it, the light is green when I turn it ON. The green light when using shuffle means "good charge" (above 25% charge). And it still plays fine, with no noticeable reduction in how long the battery lasts between charging (although I haven't measured it).

You may want to try letting it play continuously, until it stops playing. You can just leave it unattended, and check on it later. Then, turn it ON and play it some more, until it no longer comes back ON. Connect it to power, and let it charge for a few hours. That may make the green light come back when fully charged. It's good to occasionally let the battery drain completely. You don't have to keep trying to turn it ON. Just let it play until it stops on its own. Later, when you notice it's no longer playing, connect it to power.