Chosen Solution
Alright guys, so I’m having some troubles with an old flowerpot iMac. About a month ago I knocked a glass of water on the desk where the computer is sitting. There was no splash to speak of, the water just spilled around the base of the iMac. I immediately pulled the plug, but didn’t feel like doing much more, as it was 3AM. Anyway, I left it like that for over a week before plugging it back in and trying to turn it on. Well, it didn’t boot. I was kind of surprised because it was a relatively small amount of water and I didn’t think it would get inside from under the base. Now, I’m far from an expert, so I did some Googling and tried resetting the PRAM on the switch on the motherboard to no avail. I also checked the CMOS battery, which seems to still have power in it. Today, I decided to take apart the iMac for the heck of it. I cleaned it to the best of my capabilities and reseated the RAM. Tried turning it on while it was taken apart and noticed that the fan twitches when I plug it into an outlet. Nothing happens when pressing the power button. I don’t see any blown capacitors on the motherboard or psu. I tried turning it on without the HDD and optical drive connected, just in case, and again the fan twitched when I plugged it in. Any help is appreciated! Edit: Here’s the base and both sides of the motherboard. I don’t see anything around the vent holes, save for a bit of dust. Edit 2: Alright, so the photos got scaled down while uploading. Here’s a Google Photos album with the full-size images: https://photos.app.goo.gl/TiF1wUOPPoC3OI…
I think you need to go on an inspection mission! Follow this IFIXIT guide: Removing Bottom of iMac G4 15" 700 MHz EMC 1873 and look at the edge where the water likely splashed in through the bottom vent holes. Take some good detailed images of the area. If you don’t see anything visible on the top side we’ll likely y need to put the logic board out to see the bottom side. Adding images to an existing question Update (04/22/2018) OK, I don’t see anything either, which is good! I’m wondering if your PRAM battery just needs replacement. Get a fresh battery and put your system back together did that fix it?
