Is it dangerous if you drop a metal object(like a screw) on a motherboard that is powered on?

I am not very good with electricity so I can only guess. So should i be careful with screws and stuff when the pc is on?

Solution 1:

Personally, if you are "not very good with electricity", I wouldn't risk anything!

Turn the computer off and unplug the power unit.

A screw can do anything from complete a jumper down to short circuiting - and if you forget the screws for a second, there are many components that hold a charge and can hurt if you are not careful.

I remember getting a shock touching a capacitor the first time I opened a computer - not deadly, but enough force to basically lift my hand quickly (can't really explain... just imagine someone lifting your hand quick - against your will!)

So, in answer to your question, not always, but it is sometimes and more importantly, it just isn't worth the risk. Turn the power off before doing any work!

Solution 2:

Dangerous to the computer, yes. To your own safety, not much, crossing the street is much worst.

The most likely problem is an electrical short, which may divert an over-voltage, or over current to a low-voltage or low-current component, damaging it. Outside of the power supply you are not too likely to see sparks or flames (electrolytic & tantalum capacitors might be the exception to that) from shorts or damage.

I have worked on servers that were designed with hot-plug (i.e. swap in/out while stilling running) power supplies and PCI cards. The PCI card slots were lined with plastic between slots, to prevent shorting neighbouring boards while you inserted or removed a board. These features are not normally found on home or personal systems yet.

In fact I seriously avoid working (hardware wise) on a running system. I've done it, but I've understood it's my fault if I short anything. I've also killed more than one computer by various methods.

Solution 3:

The paint that they apply over the traces is not very conductive, but shorting throughholes, chip leads, and bus connectors could damage your motherboard. Avoid working on or around the motherboard when the machine is powered on, and switch off an ATX power supply completely if possible since they're on even when the computer is off.