Quaking Aspen Hybrid in Wisconsin

[HighGuy]

Actually on my property: ... I have 6 mature (30 yrs) "gray hybrid tremuloides" around my house (all sides-N S E W sides); 3 are in a line (south side) each 50-60' apart, with the west end one that has not shown a leaf as of now, Memorial weekend. I know poplars are susceptible to good hand full of problems, but, wanted to hear from more experienced, Poplar "Diagnosticians". Fast growers=fast problems! ... So, Is it time to take it down? (As I have some 5 foot saplings, growing in the bushes, 50' feet from it. Or don't plant an Aspen in a problem Aspen tree spot?) If so, should I check & sever roots, as poplars like to pass from one to another?

This is where my thoughts are at, at present. Always correct me if wrong.

Thanks, in advance!