Fixing a waterlogged iPhone 3GS
About a week ago, my wife's iPhone 3GS found its way into the washing machine and spent a good 15 minutes being washed before it was rescued. We eventually got it to work this morning. I'll quickly describe what we tried; what worked and what didn't work.
On retrieving the phone from the washing machine, my wife tried to turn it on. The phone gave no signs of life. I would have thought that it's generally a bad idea to try to fire up an electrical device whilst it's still wet (because current might flow to places that it's not supposed to flow) but it doesn't seem to have done any permanent damage on this occasion (but I'd highly recommend you don't fire up any electrical device whilst it's wet).
My wife googled for suggestions. The first resuscitation technique my wife tried was to leave the iPhone in a bag of rice for a couple of days (I was sceptical that this was any better than just leaving it to breath).
She then decided, after some gentle persuasion from me, to take the phone apart (which is surprisingly easy when you know how - see below) and we found that it was still dripping wet inside. So I'm now extremely sceptical that leaving an iPhone in a bag of rice is especially useful. Unless you enjoy carefully removing grains of rice from every orifice of the iPhone.
After taking the screen off the body and removing the logic board, we left the parts to dry on some paper towel for a couple of days.
I then put the phone back together. It wouldn't start. I plugged it into the charger and it started OK but was locked (i.e. I think the phone had detected that it had been tampered with and refused to activate without being plugged into a PC). It would turn off immediately after the charger was removed. I plugged the phone into a PC to activate the phone but the phone refused to start correctly: my guess is that it couldn't draw enough power from the USB port to start up.
At this stage it became clear that we had 2 problems:
- the battery was totally dead (or had become disconnected) and
- the phone was locked (hence we couldn't browse photos or run any apps). To unlock it we needed to plug it into a laptop but the phone wouldn't start whilst plugged into a computer.
After leaving the phone plugged into its charger and switched on overnight it unlocked itself (so we could access photos etc) but the battery was still completely flat and the phone refused to connect to the cellular network.
I decided to double-check that the battery was correctly connected. I dismantled the phone again. I cleaned all the relevant contacts with cotton buds dipped in isoproyl alcohol and then used compressed air to remove dust. After careful re-assembly, the phone behaved exactly as before. Pah.
So we bought a replacement battery for about £6 online. After installing the replacement battery, the phone works perfectly (although the screen is a little damaged).
My volt meter reported that the old battery was producing only 2.1 volts across the top two pins (compared to a normal voltage of 3.7 volts). Lithium Polymer batteries need a lot of pampering (which is usually done by the charging/discharging circuitry): if they get below a certain voltage then they are permanently damaged. 2.1 volts is, I suspect, well below the "safe" voltage for a LiPoly battery (WikiPedia suggests that the safe voltage range is 3.0 to 4.23 volts per LiPoly cell). So either the battery shorted out whilst wet, or water got into the battery and damaged its chemistry.
Conclusions and advice:
If you get your phone wet, I frankly wouldn't bother putting it in a bag with rice. Our experience suggests that leaving a phone in a bag of rice for 2 days totally fails to remove water from the internals. Instead take the screen off the phone body (so air can get to the inside of the phone) and leave it to dry normally for a couple of days. Taking the screen off the phone is easy, and this excellent iFixIt video shows most of the steps. The basic steps are:
- remove the 2 screws at the bottom of the phone, either side of the connector.
- remove the sim card from the top of the phone.
- apply a sucker to the screen (towards the bottom of the screen, near the home button). Hold the base of the phone with one hand by grasping the connector socket with your thumb and the sim slot with your middle finger. Pull the sucker with your other hand. Ideally you shouldn't let the screen pop off too quickly (as it will ungracefully rip the connectors off between the screen and the logic board) but I pulled the screen off too quickly twice and it doesn't seem to have done any damage: the connectors just pop off without breaking.
If you decide to take the logic board out then make sure you keep track of which screw goes where as there are about 4 different types of screws used in the phone. In order to remove the logic board, I had to remove a screw which was hidden under a little sticky label on which was written "DO NOT REMOVE". But I removed it. And now the phone works fine. Go figure. Moral of the story: little sticky labels lie.
(A quick disclaimer: this blog post is just a quick description of what we did to fix my wife's waterlogged phone. Whilst I've tried not to say anything really stupid; it is of course your sole responsibility if you break your phone.)