Hi @edwardishere ,
As @aactech has said, if water ingress is suspected the first thing to do is to disconnect any power from the laptop. This includes the laptop battery.
Even though the laptop is off there is still power connected to various points on the motherboard. The Power On/Off button is not a power isolating button. Its function is to signal the BIOS what the user wants to happen i.e. turn on, turn off etc. Think of the laptop as being in an extremely low power state when off and not totally disconnected from any power source
The impurities in the water causes corrosion and provides circuit paths for the electricity which were not in the laptop’s operating design and could damage the components. The corrosion starts immediately and is ongoing until it is completely cleaned away.
First do not try to charge or to turn on your laptop and then remove the battery as soon as possible from the laptop to minimize any further damage.
Then you need to dis-assemble the rest of the laptop and clean all the affected parts using Isopropyl Alcohol 99%+ (available at electronics parts stores) to remove all traces of corrosion and water. If possible do not use "rubbing alcohol" as in some cases this is only 70% IPA or less, can contain additives and is not as effective. If you do have to use it check the label to verify the amount of IPA. The higher the percentage of IPA the better
Here are a couple of links that may help.
Electronics Water Damage
Dell G7 service manual
As always with electronics, especially surface mounted pcb be gentle when handling and especially when brushing away the corrosion. You do not want to remove any components from the board. Remove the shields that may be covering some components as the water may have got in under there. The ends of any flex cables and their connectors need to be cleaned as well
Hopefully after you have done all this the laptop might possibly work correctly again.
If this process seems too daunting, take your laptop to a reputable, professional laptop repair service, experienced in liquid damage repair and ask for a quote for a repair. If you decide to do this, do it sooner than later.
* You do know that when water damage is suspected you should immediately take out the battery and unplug the charger from the laptop?
* Why do you think it was not water damaged?
* When you opened the back did you see water droplets?
@aactech Thanks for the reply! This happened to me yesterday while I was traveling. It was stored in my waterproof backpack which usually holds up very well against the rain. But this time some raindrops must have went through (It was raining badly). I found my laptop can't be turned on on my train ride and I did not have the right tools to open the back cover. I went to best buy today to get it checked and purchased the toolkit.
When I found my laptop was in that condition, it was overall dry. Well I think it can be classified as water damaged, but it can still be turned on just not running the system. Instead of completely dead. I'm assuming it's the overall moisture that is preventing it from turning on instead of certain parts are damaged. I'm not an expert, it is a assumption I made after some searches online and conversation with friends who know better.
Edward You さんによる