Besides not using a microwave or a tempering machine...
Unless there's water in the container you're using to melt the chocolate, I don't think the chocolate is seizing as you're burning the cocoa butter (which has a very low smoke point). In the microwave, use 50% power, you need it low so that you don't burn in. Hopefully, you're chopping up the chocolate and not heating the whole chunk. At first, go about a minute at 50% power, then stir the chocolate a little to use that residual heat to help melt what chunks are left. Then I would go at about 15-30 sec intervals, then stir again. Do you plan on seeding the chocolate to temper it? If you have access to MyCryo, use 1% by weight of MyCryo. Melt the white chocolate to 35C and add the MyCryo. Then let cool to 29C and the chocolate will be ready. MyCryo is just the beta crystals from the cocoa butter. Cocoa butter has many different fats, but if there was only the beta crystal, we wouldn't have to worry about tempering. Tabliering is still my prefered method of tempering, as it doesn't incorporate much air, but MyCryo does make life easier when you're in a rush. Hope this helps.
