Cal. Business and Professions Code § 21303

An independent repair provider that is not an authorized repair provider shall provide a written notice to any customer before providing repairs that contains the following information: (a) The independent repair provider is not an authorized repair provider for the product. (b) The consumer may wish to review the terms and conditions of any warranty for the equipment, as repairs not performed by a designated authorized repair provider could potentially affect the warranty. (c) Warranties for consumer products are governed by the federal Magnuson-Moss Warranty Act (Chapter 50 (commencing with Section 2301) of Title 15 of the United States Code), which gives consumers rights and protections that apply over any conflicting provisions in the warranty. (d) Under Magnuson-Moss, a warranty cannot generally require that maintenance repairs be performed only by an authorized repair provider, unless the Federal Trade Commission waives this prohibition, or the repair is provided free of charge, pursuant to that warranty. (e) Under Magnuson-Moss, if damage to equipment is shown to be caused by faulty nonbrand equipment or by faulty repair by a nonauthorized repair provider, that damage may not be covered by the warranty, but the warranty may otherwise remain in effect. (f) Under Section 14019.4 of the Welfare and Institutions Code, an independent repair provider that is a Medi-Cal enrolled provider is prohibited from seeking reimbursement or attempting to obtain payment for the cost of covered services from a Medi-Cal applicant or recipient, unless the beneficiary owes a share of the cost, as described in subdivision (g) of that section.