Can eBay issue full refund for item to be sent back?

I bought an iPhone and it wouldn't turn on even after plugging it into itunes. I filed a complaint/case and i want a partial refund so i can fix it myself because i want the item. He insists to having myself issue a full refund of $310 but i'm asking for $150 or $100, i really want to keep the item so i can fix it, he really wants me to close the case but i will not. Any tips? And after the case escalated can eBay force me to make a full refund to send the item back?

No smart seller will ever issue a partial refund. Sorry, but it's all or nothing.

Return it for a full refund.

And yes, Ebay will require you to return it to the seller before you get a refund.

If you keep harping on a partial refund, you will end up with a phone that doesn't work.

Ebay hates partials as much as the sellers do.