T450s doesn't wake from sleep

[hyde]

So far I tried updating BIOS (now on JBET69WW 1.33 ), removing the removable battery, keeping it plugged in, updating power drivers, I even re-installed Lenovo service bridge and System Update to see what other drivers needed updating,and I updated most of the critical and recommended ones there are only few unrelated ones remaining like FP reader, SSD, intel technology access

When I leave it in sleep for longer than an hour or so, (I don't know what's the exact cut off), nothing wakes it up. The power button keeps fading in and out indicating it's asleep, but hitting power does nothing.