# Why can't I turn on my cellphone without removing the battery?
**URL:** https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676
**Category:** Factual Questions
**Created:** [October 1, 2010, 12:27am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676 "2010-10-01T00:27:26Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 1, 2010, 12:27am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/1 "2010-10-01T00:27:26Z")
Last weekend I pulled my cellphone out of my pocket to make a call and it was off (I always keep it on).
This is my phone: [Samsung SGH-D407 / D347 Specs, Features (Phone Scoop)](http://www.phonescoop.com/phones/phone.php?p=901) (the D407)
The button on the upper right with the picture of the red telephone handset is the on - off button.
I tried using this button to turn it on. Nothing. So I tried removing the battery and putting it back. This worked!
I made my call. Then, as an experiment, I turned it off. I could not turn it back on again without again removing the battery.
So currently the only way to turn it on is to pop the battery and then put it back. As long as I keep it on it’s fine. As far as I can tell everything else works fine. The red on - off button is obviously making a connection and being sensed, because I can use it to turn the phone off. But it won’t turn it on.
I suspect this is some kind of battery problem and that a new battery might fix it, but I’m not convinced.
Have any of you had a similar problem? Did purchasing a new battery fix it? Any electronics engineers here who can tell me what might be going on?
(I know that I should probably just get a new phone. It is a few years old. But I’d hate to replace it if it’s something simple like the battery.)
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [October 1, 2010, 2:08am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/2 "2010-10-01T02:08:30Z")
Did putting the battery back in cause the phone to turn on without pressing the button?
If so, I would guess you have a bad keypad, with a stuck key.
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 1, 2010, 2:16am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/3 "2010-10-01T02:16:24Z")
Yes putting it back in causes it to come on on it’s own.
I thought of the stuck key possibility. However, when it’s on, all of the keys seem to work. This includes the red key which, in addition to being the on key, can also be used to turn if off, end calls, and other things. So the key seems to be fine and all of the others seem fine also.
If it’s a stuck key, wouldn’t other things not work?
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [October 1, 2010, 2:30am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/4 "2010-10-01T02:30:54Z")
> [@davidm](#):
>
> Yes putting it back in causes it to come on on it’s own.
>
> I thought of the stuck key possibility. However, when it’s on, all of the keys seem to work. This includes the red key which, in addition to being the on key, can also be used to turn if off, end calls, and other things. So the key seems to be fine and all of the others seem fine also.
>
> If it’s a stuck key, wouldn’t other things not work?
It’s possible that there is enough leakage current through the On/Off key to mess up the phone’s power-on circuit. If you are brave, you could take the phone apart and clean the switch membrane. Did you ever spill anything on the phone?
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 1, 2010, 2:37am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/5 "2010-10-01T02:37:28Z")
When I took the battery out (the first time it didn’t work) there did seem to be some moisture on the battery (on the side facing out). I wiped it off but I’m not certain that it wasn’t a trick of the light or something. I don’t know how water would have gotten into it.
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 1, 2010, 3:17am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/6 "2010-10-01T03:17:49Z")
What’s involved in taking it apart?
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### Author:  [@beowulff](https://boards.straightdope.com/u/beowulff)
#### Post date: [October 1, 2010, 3:22am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/7 "2010-10-01T03:22:28Z")
> [@davidm](#):
>
> What’s involved in taking it apart?
I haven’t worked on that particular phone, but there are usually some hidden screws in the battery compartment, and lots of snaps. Not for the faint of heart…
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### Author:  [@astro](https://boards.straightdope.com/u/astro)
#### Post date: [October 1, 2010, 5:15am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/8 "2010-10-01T05:15:38Z")
> [@beowulff](#):
>
> > [@davidm](#):
> >
> > What’s involved in taking it apart?
>
> I haven’t worked on that particular phone, but there are usually some hidden screws in the battery compartment, and lots of snaps. Not for the faint of heart…
Before disassembling it it might be prudent to open up the back, take out the battery and direct a fan at the empty battery cavity for at least 12-24 hours. Preferably in relatively dry environment. You could also stick the phone with the back open in a bag of uncooked rice for a day or so to pull any moisture out.
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 1, 2010, 11:01am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/9 "2010-10-01T11:01:59Z")
> [@astro](#):
>
> > [@beowulff](#):
> >
> > I haven’t worked on that particular phone, but there are usually some hidden screws in the battery compartment, and lots of snaps. Not for the faint of heart…
>
> Before disassembling it it might be prudent to open up the back, take out the battery and direct a fan at the empty battery cavity for at least 12-24 hours. Preferably in relatively dry environment. You could also stick the phone with the back open in a bag of uncooked rice for a day or so to pull any moisture out.
I’m pretty good with electronic stuff but I’m nervous about disassembling a cell phone. I disassembled a broken calculator years ago and ended up with a handful of tiny springs and stuff that I couldn’t reassemble.
The fan might be worth a try. I’ve considered turning a blow dryer on it. I suppose I should be a little careful about that. I’m not sure what affect too much heat might have on some components. It might not be good for the display or the camera for example.
I’d be a little concerned about sticking it in a bag of rice with the back off. Couldn’t I end up with rice jammed in various nooks and crannies?
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 1, 2010, 6:01pm UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/10 "2010-10-01T18:01:37Z")
Thinking about this some more, I probably will try to dry it out with moving air but I’m skeptical that it will do any good. This started a week ago and is still happening. If there was moisture inside messing things up, wouldn’t it have evaporated by now?
I still wonder if maybe it’s a battery issue. If the battery’s output is slightly compromised (by age or whatever) could it be that the slight undervoltage (or whatever) wouldn’t be enough to keep it from working, but might be enough to keep it from being sensed when I try to turn it on?
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### Author:  [@ChrisBooth12](https://boards.straightdope.com/u/ChrisBooth12)
#### Post date: [October 1, 2010, 10:42pm UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/11 "2010-10-01T22:42:02Z")
a few years old? get a new phone. a battery for it even if you could find one would be like 80 bucks just get a new phone
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### Author:  [@NOLA\_Cajun](https://boards.straightdope.com/u/NOLA_Cajun)
#### Post date: [October 2, 2010, 12:05am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/12 "2010-10-02T00:05:21Z")
If you’re on a plan I would think you’re eligible for a free upgrade. I can’t imagine spending so much time and effort on an old cell phone. If you go to your local cell phone store (for whatever company you use) they would probably even transfer all of your data for you. If it’s a pre-paid then call their customer service and they may even send you a phone for free. I understand liking to make things work again but cell phones like yours are basically throw-aways.
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### Author:  [@astro](https://boards.straightdope.com/u/astro)
#### Post date: [October 2, 2010, 12:09am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/13 "2010-10-02T00:09:17Z")
Replacements for that phone are $5 used to $25 new on ebay.
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 2, 2010, 2:26am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/14 "2010-10-02T02:26:05Z")
> [@astro](#):
>
> Replacements for that phone are $5 used to $25 new on ebay.
Not that I have to have that model, but I can’t find any new SGH-D407s on eBay. Where did you see it?
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### Author:  [@Imasquare](https://boards.straightdope.com/u/Imasquare)
#### Post date: [October 2, 2010, 2:45am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/15 "2010-10-02T02:45:12Z")
> [@davidm](#):
>
> > [@astro](#):
> >
> > Replacements for that phone are $5 used to $25 new on ebay.
>
> Not that I have to have that model, but I can’t find any new SGH-D407s on eBay. Where did you see it?
You can buy a new battery for your model on ebay for $4.80 with free shipping.
> **[Pardon Our Interruption...](https://www.ebay.com/splashui/challenge?ap=1&appName=orch&ru=https%3A%2F%2Fwww.ebay.com%2Fitm%2F120616496016%3Fpt%3DPDA_Accessories%26hash%3Ditem1c154dab90&iid=2dff0fa3-27c1-43c3-aaa4-bc1ea0bda033&iim=XMTg0LjB&iia=pDEwNS45FV&iiz=aVnOS4xMDA*ClT)**
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 2, 2010, 2:50am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/16 "2010-10-02T02:50:08Z")
I noticed that, but I’m not convinced that the problem is with the battery.
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 2, 2010, 2:54am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/17 "2010-10-02T02:54:08Z")
I just found the paperwork for the phone. I got it for joining a plan about 2 1/2 years ago. I think most plans are 2 years so mine is probably up. If so I can probably get a free replacement from ATT for signing up for another 2 years.
It works other than this one annoying thing, but that one thing may just be the start.
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### Author:  [@astro](https://boards.straightdope.com/u/astro)
#### Post date: [October 2, 2010, 3:50am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/18 "2010-10-02T03:50:17Z")
> [@davidm](#):
>
> > [@astro](#):
> >
> > Replacements for that phone are $5 used to $25 new on ebay.
>
> Not that I have to have that model, but I can’t find any new SGH-D407s on eBay. Where did you see it?
In reviewing completed listings of what that phone sold for. There are also tons of good condition used ones for even less which you can buy or the cost of a beer or two.
Here
> **[Pardon Our Interruption...](https://www.ebay.com/splashui/challenge?ap=1&appName=orch&ru=https%3A%2F%2Fwww.ebay.com%2Fitm%2F230532032653%3Fpt%3DCell_Phones%26hash%3Ditem35acc7a88d&iid=6ad4e72c-d6a7-4c1a-ac7b-63a9ed9adec5&iim=OMTg0Ljt&iia=ZaEwNS45mf&iiz=QGcOS4xMDA*jjN)**
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### Author:  [@Cell\_Guy](https://boards.straightdope.com/u/Cell_Guy)
#### Post date: [October 2, 2010, 4:42am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/19 "2010-10-02T04:42:00Z")
Taking that phone apart is a piece of cake. There should be four screws on the back of the device. A jewelers screwdriver with a Phillips head will work best. After the screws are out you’ll want to separate the front and back covers. A credit card will work best for that. Make sure you take the back cover off, not the front. The hinge connects on the front cover and you don’t want to mess with the hinge.
After the front cover is off you’ll see the flex cable that attaches to the board and goes through the hinge to the LCD. The connector pops right off. Once this is done you should be able to remove the main board.
After removing the main board turn it over. There will be a white mylar that sticks with adhesive to the board. This is the keypad. Do not remove the mylar–it will most likely tear and once it tears it’s useless. Look at the area of the keypad where the on/off button should be. Look specifically for moisture under the mylar. If there’s moisture you’re probably out of luck. The board under the mylar has probably started to corrode and there’s no way to fix that outside of replacing the phone. Even if you don’t see moisture that doesn’t mean it wasn’t there at one time. Corrosion would still be there and corrosion is not your friend.
BTW, I fix cell phones for a living.
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### Author:  [@davidm](https://boards.straightdope.com/u/davidm)
#### Post date: [October 2, 2010, 5:08am UTC](https://boards.straightdope.com/t/why-cant-i-turn-on-my-cellphone-without-removing-the-battery/555676/20 "2010-10-02T05:08:03Z")
So what exactly would be the point of taking it apart? If I see moisture, it’s not fixable, I get that. What if I don’t see moisture? What am I looking for that would be fixable?
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