Norman W Port Charlotte , FL March 05, 2016 Appliance: LG Microwave Oven LMVH1750ST Lg Microwave Lmvh1750st / As1elga: The number 3 and 9 did not work on our microwave. How to replace Parts Assembly. I looked up the model number of the microwave. Went to the Q&A area stated the problem and they came up with the replacement part. I ordered the part and installed it right after it was delivered. Works great, I labeled the wires that I had to disconnect, removed the touch pad unit and replaced the broken part, reassembled, plugged it back in and it worked fine. Thank you for your service. Norm West Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes