I dropped my LG Optimus in water this morning. It was totally submerged for probably 3-4 seconds. I pulled the back cover and battery off within a couple of minutes and dried everything the best I could. I let it set for a couple of hours, then used low pressure compressed air to dry further if needed. I also pulled out the microSD card, which did not appear to be wet. After I thought it was dry enough, I put the battery back on and powered it on. Everything on the phone is operational, except when I place or recieve a call, I can't hear whoever is on the other end...I can switch it over to speakerphone and can hear fine....not sure if the other end can hear me as I have only dialed numbers to places that use automation (my bank, which has an Audio Response Teller)....texting is fine, camera is fine, no problems with screen or any buttons....just the call feature. Anyone had this problem? My guess is that I'm looking at having to completely replace the phone...
Liquid damage will likely have corrosion set in within a couple days especially with power running through the circuitry. Most likely the earpiece speaker shorted out. Liquid damage would not be covered in a service and repair location. If you have Sprint's Total Equipment Protection (TEP) you can order a replacement device at www.sprint.com/protection and it will be shipped overnight to you. I believe the Optimus S is a $50 deductible, but the site will tell you for sure what the deductible would be.
The Sprint Total Equipment Protection plan allows you to replace your phone with a $50 deductible. Let's say you've owned your Optimus for 6 months. 6 x $7 = $42 + $50 = $92. You can buy an Optimus online for a similar price. In other words, insurance only makes sense if you lose your Optimus more frequently than every 6 months. That's not likely to happen. Just give it a couple of days, and I think your phone will be functional again.
If something like this happens again, try using your vacuum cleaner (handheld attachment) instead of an air compressor. You want to draw the water out of the cracks, and not force water deeper into your device. If it's been less than a day, your phone may still have moisture inside of it, causing the speaker not to work. I would recommend to leave the battery out for a couple of days. You know those little packs that say "do not eat" and come inside of shoes or clothing? If you have any of those, try packing them around the phone. I read somewhere that it may help draw moisture out of the phone.
The first night I had my phone, it fell off of the couch into a cup of water, and was powered on. I couldn't make or recieve calls. Sprint wanted $100 to replace the phone. A friend reccomended that I pack the phone in dry rice. I tried this for about 4 hours and the phone turned back on and I have been using it since. The rice drew all moisture out of the phone.