A few days ago, I shared the story of my phone, the tragic event of it being waterlogged -:
I will spare you from reading the whole blogpost. In short, My phone fell into water, I took it to service center, service center guy sent it to company, the company guy told him it would cost me Rs. 6000/- since motherboard was damaged. The service center guy told me that it would cost me Rs. 6000/- since motherboard was damaged. I refused since the new phone itself cost me Rs. 9000/- and I didn’t trust the service center guy. So I got the phone returned to me without any repairs.
The phone was actually booting, but after the boot logo, it used to turn off. I have always been opening things from my childhood. I sometimes make electronic circuits, repair small things which I can easily understand etc. Since I had never repaired any mobile in my life, I was reluctant to open it fearing I would mess things further. But then I thought there was nothing left to mess up since I was planning to buy a new phone anyway. Moreover, the idea of getting out the 3200 mAH battery (my phone had 3200 mAH battery) was also intimidating. So I decided to go with it.
Logically thinking, What does exactly water do? Well, water itself is a bad conductor of electricity (Try collecting distilled water and checking its conductivity). But, the salts and electrolytes dissolved in it causes it to conduct electricity. So, when water goes inside the phone, it does 3 things -:
1) It may damage the screen. Which surely costs around 30-50% of the mobile price.
2) If you ever have seen a mobile circuit board (PCB), the components and their contacts are very close to each other and tiny as well. So the water may penetrate between the contacts and result in conduction where there should not be any. (Short Circuiting). It may result in permanent damage of the components if the current supply is not turned off soon.
3) After water dries up, it generally leave scales (The kind you might be seeing in your kitchen sink). Scales are just deposition of salts and calcium. So the scales may or may not cause a permanent connection between contacts. (I said may or may not because, salt themselves in solid form, are bad conductors. But only when mixed with water or moisture, they conduct pretty well.)
Water can’t directly penetrate inside the individual components since they are sealed (All ICs, capacitors, resistors, inductors etc are built fully enclosed in Plastic cases).
Generally in new electronics era, processors and ICs have the functionality that if they detect any short circuit or malfunction, they can turn themselves off to avoid any further damage to circuitry. Since my phone was turning on and then going off, there was a strong probability that scaling might be causing a short circuit somewhere and there was a hope that electronics wasn’t damaged. So I decided to open it.
As soon as I removed the cover, I was able to see the scaling. The service center guy didn’t even try to clean them.
A phone is divided into modules. That means, everything is separable from the main PCB. So I detached everything… The cameras (Back and Front), Screen cable, battery cable, speaker cable, WiFi antenna cable and the charging connector module cable.
Then I started attaching them one by one to see in which module the problem was. First I attached just the mainboard and battery. When I tried to switch it on, nothing happened. How could anything would have happened since the screen wasn’t even connected 😛 . So I connected the screen too and now tried to switch it on again. Then there was the boot logo… I was praying Please go past that… Go past that.. and that’s when the prayers were answered… There was the boot animation and then the most beautiful words… “Enter PIN to Unlock” 😀 😀 😀 . I was delighted. Motherboard damage?? LOL 😀 .
I switched it off. This time I attached every module except the charging connector pin module and switched it on. Same result. It switched on perfectly 🙂 .
Therefore as the diagnosis suggests, the problem was in the Charging connector module. I saw it more carefully and Voilla! I found that there was severe deposition of scaling in the connector which was resulting in short circuiting.
After that, I realized I was getting late to come to office. So I will clean it at night and hopefully bring it along with me tomorrow 🙂 .