Good afternoon, my name is ***** ***** I will assist with your query today.
The most likely cause is a hardware fault, the fact it has been refurbished suggests they may have not correctly inserted a RAM or module properly.
If the seller is nearby I would take it back to them and ask them to strip it down and make sure all the components are correctly installed.
Alternatively if you would like to do this
Start by removing the power supply and battery, then remove the top case, check the ram is correctly seated, disconnect the optical drive, remove airport card. Then connect the power supply (without the battery), and turn on and see if you get to the logo, if you do start by adding each component you remove above (restarting each time), until the fault occurs to find the culprit.