Optiplex 7050 SFF not turning on after force shutdown

The PC was running well until it hung, and to recover it, I forced a shutdown by pressing and holding the power button. Now, after that, it is not turning on again. Nothing happens when I press the power button. I tried removing every cable and connector and reinserted the RAM and CPU. Still, nothing happened. I also changed the CMOS battery. The power supply glows green for a second when I connect it to the power cord — and that's it.