You either have to add a vertical post to hold it up or change the hinges to torque hinges. I had an old Linn on which I used some of these and it worked perfectly and holds up a 5lb lid even at 30 degrees. You can get even stronger ones from Sugatsune.
https://www.progressivepii.com/sugatsune-specialty-hinges-1-63-64-l-x-1-11-16-w-x-5-64-thick-stainle...
https://www.progressivepii.com/sugatsune-specialty-hinges-1-63-64-l-x-1-11-16-w-x-5-64-thick-stainle...