While there's generally no reason you can’t change a microwave light bulb yourself (given the proper precautions), with a GE microwave, the warranty may be void under the following circumstances: Misuse or lack of proper maintenance: What this means is if you make any mistakes while changing the bulb, the microwave’s repair will not be covered. Alterations to the product: Any changes that negatively affect the product’s performance won’t be covered by the warranty.