Hi Eric, Thank you for the help. Here is what happened to me. I put the good Q502 in, put the 200W lamp in serial with AC. disconnect degause. The lamp is bright as a 60 W lamp. But this lasted only for about 15 second. Then I heard a spike on the Power Board. The lamp is not on anymore. I found Q601, Q602, R607 and Q502 all damaged again. Any suggestion ? Jeff