No.

引用自 HissingPython：

No.

Oh brill, I won't have to splash out 250 quid haha.

if it happened in the past and it wasn't on then no, nothing bad should happen

you should worry if it was on or the screws struck a capacitor or something else

If the PSU is operating without strange noises, smell, instability, or coil whine, then it's probably fine.

引用自 ArielNugie：

If the PSU is operating without strange noises, smell, instability, or coil whine, then it's probably fine.

I think I have coil whine

引用自 R3dAlert93：

引用自 ArielNugie：

If the PSU is operating without strange noises, smell, instability, or coil whine, then it's probably fine.

I think I have coil whine

You're probably fine. Coil whine by itself doesn't mean the PSU is failing. It's just the inductors vibrating under electrical load. It's annoying, but not dangerous, and it doesn't reduce the lifespan of the unit.

The things to actually watch out for are:
burning smell
random shutdowns or reboots
unstable voltages under load
fan noises that get suddenly harsh or grinding

If none of those are happening, the PSU isn't failing. Coil whine is mostly a noise comfort issue and not a reliability issue.

If the noise is really bothering you, sometimes limiting FPS, enabling Vsync, or trying the PSU on a different outlet can reduce it. Otherwise, some manufacturers will accept an RMA if the whine is particularly loud.

as long as the loose screws were removed its fine
if the psu is off its not going to damage anything

if the psu was on and screw dropped in, it could short rails, sensors, or mains
which could weld the screw into place, causing more damage to the psu

but while off (unplug or switch, not soft turn on/off) it should be fine, mains caps drain in a few minutes leaving it nowhere to short and weld to or damage anything

引用自 _I_：

as long as the loose screws were removed its fine
if the psu is off its not going to damage anything

if the psu was on and screw dropped in, it could short rails, sensors, or mains
which could weld the screw into place, causing more damage to the psu

but while off (unplug or switch, not soft turn on/off) it should be fine, mains caps drain in a few minutes leaving it nowhere to short and weld to or damage anything

Drain the power by holding the power button for 10 seconds? I got told that by computer technician if you dissemble something make sure to be grounded and unplug the psu cord and hold the power button for 10 seconds until the power is drained fully from the rig.