Power on/off HDD indicator and stuff

I'm pretty sure that my tower case will phsically accept a decently modern
mboard. It's designed to take full ATX size, the mboard in at the moment is
a bit smaller than that length-wise, and it will, I feel sure, fit a minATX
mboard. I'd have to get a new ATX PSU with the more up-to-date power
connector for modern mboards.

But something troubles me. The case (about 11 years old) has a mechanical
on/off push button. Also a mechaical "sleep" push button. There is a LED for
"HDD" and a LED for "sleep".

I'm not sure if I need to post pictures of the wiring and plugs associated
with the above, but anyway can anyone say whether I've got a major
"difficult to solve" problem here concerning a mboard made say during
the last 3 or so years? (I'm wanting to buy a mboard of about, well,
say 2.0 - 3.0 Ghz speed, with PCIe, that could be used as a
workstation).TIA.


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