there's a couple of errors that pop up ..if you tell us we could help but id hold off on buying one from ebay...
there could be three reasons why.
1.big memory card like 32gig+ has trouble..it wouldn't accept my two 32gig sd cards so i have one sd as 32 and a other as 1 = out to 33gigs ... so keep it under 33gigs
2.you dropped ur psp or ur finger accidentally pulled the memory card out while loading /saving..this can also happen in the xmb and the system id did not recognized that ur MS was removed causing an error while trying to insert ur MS causing it to fail the load all the time...id' say reset ur flash 1 and if that doesn't do the trick uninstall what ever cfw yu have ..or ofw if you have that instead and either down grade or upgrade (if you can) and reinstall what ever firmware you have an that should work because that's what happened to me and psp.
3.sadly this has a error code that means you reader is F.U.B.A.R. and needs replacement ..but the only replacement i know is getting a new board instead of getting a whole complete psp an paying alot for it ... this happened to me back in 08 on my 2g psp the psp mem stick reader was F.U.B.A.R.
and could not be replace with out solder so i bought a psp mother board for about $20 bucks and did the job fine.
i encounter these three on my life time with the psp..hopefully i helped gud luck sir on ur psp