Jennifer N Middletown , MD April 30, 2019 Appliance: LG Electric Range LRE30453ST Lg Range Lre30453st / : 7 error. How to replace Pwb(Pcb) Assembly,Sub. Opened the back panel and saw that one of the relay terminals was melted. Replaced with a new pcb assembly. The oven fired right up. 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes