Answer: It sounds as though you have addressed all the common problems: insects, compaction, thatch. That leaves diseases as a culprit but I can't diagnose the problem without actually seeing it. You might try raking the areas again this spring and reseeding. If the new grass dies out, there may be a fungal disease residing in the soil. Without knowing just which one, I can't really suggest a control. But you've ruled out everything else.... Good luck with your turf!
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