On the new charges your boyfriend has a right to a jury trial where the prosecution has to prove his guilty beyond a reasonable doubt.
On the probation violation your boyfriend ONLY has a right to a HEARING In front of a judge and NOT a JURY. The DA must prove your boyfriends guilt on the violation of probation by preponderance of the evidence = more likely than not that he is guilty. THIS IS AN EASY BURDEN. Just about EVERYONE looses the probation violation hearing. So he'd better be pretty confident in his defense.
If found in violation of the probation then the judge can and most likely will send him to prison for the 3 years. A good attorney is absolutely necessary to work this out, get this dismissed or fight the charges.
The above information does not establish an attorney client relationship nor is it meant to provide legal advice.
Joint suspension means he received a suspended state prison sentence conditional on his compliance with the terms of his probation. If he's guilty of a new offense that will be a violation of probation (in all likelihood) but that does necessarily mean he will get the full three years. That depends on all the facts and circumstances of his case which I don't know. He will also have to defend the new charge which could bring additional time.
Bottom line you would be wise to counsel him to waive time so you can raise money for an attorney. If he still doesn't want to do that he should ask for the public defender. The PD in San Jose has some of the best criminal lawyers in the state.
Waiving time is a wise option. If he rolls the dice at a formal hearing and gets more time than what was originally offered he will not be pleased. He should set the matter on the discussion calender. In SJ those are heard on Weds morning. Find out what the preliminary suggestion is from probation. Have him write out a detailed statement as to the facts and then who ever represents him they will have good info to fight back on the time. Anytime you have a VOP it threatens to undue the original plea from the charge that put him there and work on that jail or prison sentence. The DA on this calender is tough and has the attitude "your guilty". period.
Waive time hire a private lawyer or us one from the PD. Good luck.