U2/U3 proms don't need clocks.
I'd monitor cpu pin40 (reset) which will toggle during bootup. (proves cpu is booting).
if pin40 is stuck, this is also feeding the 3 PIA's they might all be held in reset mode....
Z7,8,9,10 are all to do with prom/address decoding for various size proms....shouldn't be a problem, as your problem seems to be earlier than all that....
