Eco-Drive Skyhawk not charging

I have an eco-drive skyhawk that was given to me a number of years ago and it's been my go to for ages. Recently it seems to have died so I put it in direct sunlight to charge. Problem is it sat in that spot for a week and still nothing. I'm a bit hesitant to send it in for repair, worried that they'll just replace it instead of fixing it and this particular watch has a lot of sentimental value to me. Any ideas as to what may be wrong?