Have had a scare on my penis for about a year and it jus scabs over and falls off then re scabs. been tested for any possible std but all test where negative, what is this?

Get it seen: This may be nothing more than a picker's scab -- i'm a pathologist and should know better but i've kept things going on my upper body by messing with them especially while i'm dozing. We want to rule out a hpv lesion, or something that's been kept going by something personal. One form of premalignancy presents as excess keratin which a lay person might mistake for a scab. Good luck.

Maybe a biopsy?: I think you mean "scar". Something that scabs and heals repeatedly suggests a skin disease or a repeat injury. While std tests may be negative, it depends which ones you have been tested for (syphilis, gonorrhea, chlamydia are the most common), since human papillomavirus and others are not tested. Maybe you should see a dermatologist who can take a biopsy and confirm a diagnosis?