July 22, 2021

S4 Galaxy Repair

As near as I can tell, I bought my S4 in 2011 and it has worked fine for 10 years now. I have had to replace the battery twice (so I get perhaps 3 years per battery, which is 1000 charge cycles more or less if I charge the battery daily). That ain't too bad. The main problem I am having circa 2021 is the old version of Android. Some apps won't run on my old version, which is a minor nuisance. Other apps have bugs (such as chomp SMS, which I abandoned for that reason) running on older Android versions. But I am getting distracted.

On 7-28-2021 I replace the battery with a supposed upgrade battery. The previous RAVpower battery now barely gets through a day. I swapped in my old Anker battery, and it is worse if anything.

So, for $16 I buy a "ShenMZ" battery on Amazon. It claims a 3300 mAh rating (the original is 2500). We shall see. Often the endurance (how well it retains capacity over several hundred charge cycles) is more interesting than the peak capacity when delivered.

All this may be moot soon. Verizon has been threatening for some time to make CDMA only phones obsolete. Either do voice over LTE or go home. Supposedly this was going to be doomsday for the Samsung S4 in 2019, then in late 2020, but my phone is still going. At some point thought this phone just won't be able to make voice calls anymore and then it is on to a Google Pixel most likely.

Water damage

So, it is "monsoon season" in Tucson, Arizona. This means we are getting almost daily thunderstorms, for which we are thankful. I went on a bike ride and dropped my cell phone into a bag on my bike handlebar, not realizing that it had gotten filled with water in the latest storm. I got home and then hours later got to wondering where my phone was. I pulled it out of the bag dripping, immediately yanked it out of the case, removed the battery and got things opened up as best I could and left it in the hottest driest place I could find for a couple of days.

After that, I put the battery back in and held the button down to boot it up. It made all the proper noises and I felt the phone vibrate as it always does when it starts up, but the screen remains black. My analysis is that the processor and core electronics is OK, but the screen itself has been damaged by water. Maybe another week of drying out and I could try again, but I have another idea.

Some time ago, I bought another S4 from a guy on Craig's list. My phone is a Verizon network phone and this new one is from Sprint, so the networks are incompatible. My idea though is to transplant the innards from my phone to the Sprint phone. The hope is that the display section is identical for the two phones, we shall see.

Some notes on disassembly: My main board shows water damage along the edge near the top of the phone. There is white "crud" encrusting various parts. What I do is to get some denatured alcohol and a brush and carefully scrub this off.

The front camera, earpiece and the connector for the rear camera are a mess too. All this seems to clean off easily and nicely with alcohol and a brush. And I plan to abandon these anyway, transplanting my main board into my "donor" phone.

I transplant the rear camera from the donor to my original main board. Then I drop my main board into place in the donor phone. The trick is not trapping the cables under the board, careful checking and patience is the only trick. There are 2 antenna wires and 5 other connectors. Then back on goes the silver bezel with the plastic frame (easy!).

Before putting in the nine screws, I install the battery and give it a test. It powers up! And I see the correct stuff on the screen!

So, I power it down, install the screws and SIM card, then fire it back up. Works fine. I make 2 calls, verify that it works with Wifi, all good.


Have any comments? Questions? Drop me a line!

Tom's Cell Phones / tom@mmto.org