Do an online search for "table saw tune up" and sort through the articles to find one that gives detailed instructions on how to check for blade runout and how to test blade alignment with the table top. Here's one that covers the basics quickly and concisely, but there are many to choose from. Compare them with information from your powermtic user's guide.
It's a laborious process that will take a day or two and you need to loosen the bolts that fasten the saw trunnions/ mechanism to the cast top, and physically shift the alignment of the saw arbor relative to the mitre slots, then recheck it for alignment, etc. until you get it right. Sometimes you can loosen several corners and leave one kind of tight to shift the saw in the direction you want to move. Download the online manual from powermatic here by choosing your model and you'll have onhand a detailed parts diagram to guide you. If you're not up to a gruelling process, and don't have the appropriate tools, I recommend you re-check your blade to ensure it's not at fault and see if you can't live with it as is.
Otherwise, good luck and be patient. It's worth it to have it right, but wood is only wood, and at some point you have to just do the woodworking.

I hope this information allows you to resolve this issue. If you need further assistance, please post back with a comment to this thread.
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