return / money back policy as an ebay seller

I've been selling a lot on ebay and just recently been getting charge backs and people trying to rip me off. I recently sold a website on ebay and after I delivered everything the customer claimed he didn't get the website then after some back and forth and me providing links of screenshots etc he closed that case and opened an item not as described case. He ended up winning that case because ebay said I never responded but I always responded to the case when the customer would reply....

A week later I decided to sell my used motherboard (works / worked perfectly fine) needed to sell it to make some extra cash to compensate for losing my website and money to that previous customer and now the guy who purchased the motherboard is claiming it doesn't work.

This is getting quite frustrating. I'm afraid i'll lose this case like all the other cases. Any suggestions? What can I do about this types of things?

Leave eBay as fast as you can, this is the best solution. Mostly they care about the buyer, but not the seller.

The only thing that you can do for that case is to try and offer a refund and pay for the return shipping from the customer. At least that way you can get your item back and try to sell it again (test it and make sure it works).

Yes BigBadW is correct in that eBay will usually side with the buyer but I wouldn't necessarily say run away from eBay.