I recently purchased 2 Jelrus Infinity L30 burn out ovens on E-bay, one used one new. The used performed well for about three months. After three months the display would not ligth up but you could hear the oven heating. After reading all the tech bulletins and manuals the recommendation was to replace the printed circut board. When I priced the board it was 680.00. A little steep. I began by finding a website called Digi-Key.com. They sell electrical components for PCB's. I replaced one part at a time from my good PCB on the new oven and after 4 parts replaced I found the defective part. A crystal/occilator. When I found the exact part on Digi-Key the total cost for the part was .42. I say it so your sure I typed it correctly fourty two cents! If any one needs help with this problem please let me know. I would be glad to help. If you have one of these ovens and don't want it any more also let me know.