I am not sure because your question is too vague. I am just guessing.... Do not quote me, but Fraud usually ranges from 2 to 5 years and you can add 3 years for a prison prior. But, it could just be a parole violation and you get one year.
My standard disclaimer: I am not offering legal advice, assume I do not know the law in your state and that I am just making suggestions for starting points for when you do speak with an attorney. Do NOT rely on anything I write and contact a lawyer in your area immediately after reading my posting.
The sentencing range on the charge of Penal Code 475 (a form of forgery often charged in check fraud cases) is 16 months, 2 years or 3 years in state prison. A prior prison term within the past 5 years can add an additional one year (Penal Code section 667.5(b). If that's the charge you face and your prison prior was within 5 years, your maximum is 4 years in state prison. Whatever sentence you receive would be half time under PC 4019.