@ioannissamoilis a new display forsure. Next tear it apart and check the motherboard for any damage or corrosion from water damage. Replace the battery as well. Pst some pictures (not video) of your motherboard so we can see what you see. These guides should work for your PSP as well PSP 1000
Adding images to an existing question
@does not look to bad but there are areas of concern (could just be my old eyes) Check the Yellow area. Looks like there might be a damaged capacitor on the Right hand side. Best would be to completely remove the board and clean it with some 90%+ isopropyl alcohol, then recheck that area and let us know what you found out (post a new image after cleaning).
crwdns2934105:0crwdne2934105:0
crwdns2934113:0crwdne2934113:0
crwdns2915270:0crwdne2915270:0
crwdns2889612:0crwdne2889612:0
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