Laptop short circuit symptoms

Never have had a laptop short out but this is apparently what would happen if water gets into the circuitry. What could I expect to see?

A laptop that “flickers” while operating, starts fine but then shuts down abruptly without warning, or never starts up at all?

I don’t think there is a single answer for this. I’ve seen water, soda, and various other fluids spilled into both laptops and keyboards and the results can range from none to immediate death (of the device).

I’m not an electrical engineer but my guess is that it would ‘pop’ while starting up or while in use and then go dark.

Newer laptops seem to be more spill resistant so it’s possible that the spill didn’t reach the circuit board. But once it makes contact with electrical components on the board, then that’s probably the beginning of the end, which could happen as soon as you start it again or may not happen until there’s enough corrosion to create problems with the flow of the current.

Generally, The first thing that happens is that the keyboard stops working. Then, after some time, the entire computer will cease to function correctly. It’s very rare to have flames or smoke - usually it’s just a silent death, as the motherboard gets corroded.

The three bad things in this situation are: 1. Water. 2. Cruft (dust or things like the sugar in soda). 3. Electricity.

Pure water alone on a circuit board with no dirt or electricity has a good chance of doing no harm as long as it dries out before use.

Even if you spill pure water on a laptop there’s going to enough dirt/lint inside that it will push those things to potentially bad places.

What’s worse with a laptop is that there’s a battery supplying power to certain parts of the circuit that you can’t see so you don’t know if the liquid got into those parts. Ideally, pulling all the batteries ASAP after a spill can help. But the main battery is usually hard to remove quickly, if at all. There is also the little clock battery that’s even worse to pull. (Although it will do less damage, unless it shorts then bad stuff happens.)

Aside from a battery shorting, the power levels are low enough that you rarely get a puff of magic smoke. More likely one or more ICs will fail silently and the computer pretty much does nothing. Time to sell it on eBay “for parts”. (Take the disk out first.)

The standard procedure after a spill is to power off, try to get into wherever you can to dry stuff up. (Get the tech manual for it and try to figure out how to take off the keyboard, etc.) Let dry for a week or two. Power back on under battery power. Cross fingers.

I had a laptop that kept shutting down abruptly for no apparent reason. It was under Geek Squad warranty, so I took it in. Turns out an internal screw had come out, causing a fan to unseat, and it was overheating. I couldn’t tell from touch it was overheating, and it wasn’t displaying an error message before it shut off, because the part that was overheating wasn’t the CPU, it was something to do with the screen. It wasn’t technically shutting down-- the screen was just going dark. It was a failsafe, and I never lost any work. Mostly just annoying.

I have no idea how the screw came out. I did travel with it once in a carry-on, but mostly it just traveled around my apartment. I never dropped it. I have a feeling it wasn’t well-seated to begin with. Fortunately I had kept my old one, so I had a back-up. It had Win8 on it, but I pulled a boot copy of 10 from the busted one onto a USB just before I took it in, and used it to upgrade the old one. Was kind of surprised it worked, but it did.

Ok cool, what about super-high humidity condensing on the internal electronics while the laptop’s on?

And generally does something burn/overheat if short circuited?

The only way you are going to get condensation is if the laptop is cooler than the surrounding air. That’s really unlikely for an operating laptop, since they generally get warm.

ETA: “short circuit” is much too broad a term. For a logic IC, a short circuit might pass a few microamps, so clearly no smoke or fire.

The tolerances on many connectors on the main chips like the CPU and GPU are so very, very high that a tiny change in current on them will prevent the computer from running properly. Far lower than the delta current needed to cause something to pop. So just a wisp of a bit of conductive-ish cruft will do it.

Sorry, confused…do you mean the tolerance is very low or very high?

“High” in the sense of a very, very narrow window of expected signal characteristics. Not just voltage out of range but the “shape” of the signal, etc.

Sorry if I didn’t use the right term.

My personal experience is that you get some weird behavior for a second or two and then the whole system shutsdown before you have a chance to cut power. I suspect that it was specifically designed to fail that way to try and avoid permanent damage, but I don’t know that for a fact.

What I do know for a fact is that you should remove power as quickly as possible–both the battery and any outlet, and let it dry out completely. Don’t take chances. I leave the laptop open and face down to let water run out, while putting it on something like a milk crate to keep air circulating and allowing evaporation. And I let it go for a full 48 hours.

When it happened to me, it simply didn’t start up at all. After a trip to Apple care and a bill for $1200 to get it fixed, I decided to open the damn thing up and swab out the visible corrosion (minor) with rubbing alcohol. Seven years later, it’s still working. Won’t work most of the time but did with mine.

But, anyhow, I can’t see there being a consistent set of symptoms for this, as there’s so many possible components that can go wrong. But, since you asked, for me it was–to be exact, no start up screen, chime or anything. Flicked it on, and it just stood there.