What does it mean dead testicle has no symptoms? does it look like actual testicle?

Same sexual function: no symptoms probably means no pain it could also mean no sterility and no loss of sex drive if your other testicle is normal since that normal testicle would provide the same function as two testicles if one testicle was dead it would probably be smaller than the normal testicle although it could be of the same size usually the good testicle becomes larger , called compensatory hypertrophy