Sanyo 4920: Mysterious prob. repairable?

I don't know if any here have experience on the hardware side,
particularly with this phone, but my wife's is doing something
inexplicable and I think it might be ready to go to its reward.

She'll suddenly find the battery totally drained. It's not
like it empties more rapidly than usual, as a Li-On battery would if
it's been recharched too many times. It'll seem fine, and then poof.

I actually bought a new battery for it, but the same thing
happened again.

The difficult part in all this is that my contract ends June
1st, and I'll happily re-up for the $300 in phone rebates (I always
buy my wife and myself the same phone, and that's how I got these for
next to nothing). I don't pay for the insurance because we've never
lost or damaged a phone so as to warrant needing it. This is sort of
an annoying first.

So my question is whether it's worth thinking about repairing
it, or simply spring for a new phone now and some time or another in
the future take advantage of renewal rebates.

Is anyone familiar enough with the way these things work to
know whether it's the cellular phone equivalent of a mainboard failure
(which would clearly call for a new phone) or if these things are
occasionally caused by dirty terminal contacts or something?

Thanks for any advice, DGI

---

› See More: Sanyo 4920: Mysterious prob. repairable?

"David G. Imber" <[email protected]> wrote in message
news:[email protected]...
> I don't know if any here have experience on the hardware side,
> particularly with this phone, but my wife's is doing something
> inexplicable and I think it might be ready to go to its reward.
>
> She'll suddenly find the battery totally drained. It's not
> like it empties more rapidly than usual, as a Li-On battery would if
> it's been recharched too many times. It'll seem fine, and then poof.
>
> I actually bought a new battery for it, but the same thing
> happened again.
>
> The difficult part in all this is that my contract ends June
> 1st, and I'll happily re-up for the $300 in phone rebates (I always
> buy my wife and myself the same phone, and that's how I got these for
> next to nothing). I don't pay for the insurance because we've never
> lost or damaged a phone so as to warrant needing it. This is sort of
> an annoying first.
>
> So my question is whether it's worth thinking about repairing
> it, or simply spring for a new phone now and some time or another in
> the future take advantage of renewal rebates.
>
> Is anyone familiar enough with the way these things work to
> know whether it's the cellular phone equivalent of a mainboard failure
> (which would clearly call for a new phone) or if these things are
> occasionally caused by dirty terminal contacts or something?
>
> Thanks for any advice, DGI

David, it's possible that the battery contacts on the phone might be dirty.
Try using a pencil eraser to clean them up. Check the contacts on the
charger as well. If that doesn't work, take the phone to your local SPCS
store and ask them to run diagnostics on it.

Bob

On Tue, 18 Apr 2006 13:42:52 GMT, "Bob Smith"
<[email protected]> wrote:


>David, it's possible that the battery contacts on the phone might be dirty.
>Try using a pencil eraser to clean them up. Check the contacts on the
>charger as well. If that doesn't work, take the phone to your local SPCS
>store and ask them to run diagnostics on it.

I did that, Bob, and the phone passed all the tests without
any problem. It's in good condition, and for what it's worth, the tech
admitted that despite the fact they're discontinuing it, the Sanyo
4920 remains one of the best phones they've ever carried.

So I asked him what could have possibly made the phone appear
to lose power completely all of a sudden. He said he's seen it happen
before, but didn't have an answer.

He did suggest something I was not aware of, and I wonder if
others follow this: that the phone should always be charged with power
off, and as soon as the "fully charged" symbol appears, should be
removed from the charger. I admit that I always charged my phones with
them on, but he suggested that this resulted in incomplete charging.
I'd also always been under the impression that once it's charged, you
can leave it on the charger indefinitely with no further effect on the
phone.

He also advised me to turn the phone off when I'm on the
subway (where there are generally no signals) for obvious reasons
(searching drains battery). But this is rather inconvenient and I
doubt many people would take the time to do it.

Thanks for your advice, DGI

"David G. Imber" <[email protected]> wrote in message news[email protected]...
> On Tue, 18 Apr 2006 13:42:52 GMT, "Bob Smith"
> <[email protected]> wrote:
>
>
>>David, it's possible that the battery contacts on the phone might be dirty.
>>Try using a pencil eraser to clean them up. Check the contacts on the
>>charger as well. If that doesn't work, take the phone to your local SPCS
>>store and ask them to run diagnostics on it.
>
> I did that, Bob, and the phone passed all the tests without
> any problem. It's in good condition, and for what it's worth, the tech
> admitted that despite the fact they're discontinuing it, the Sanyo
> 4920 remains one of the best phones they've ever carried.
>
> So I asked him what could have possibly made the phone appear
> to lose power completely all of a sudden. He said he's seen it happen
> before, but didn't have an answer.
>
> He did suggest something I was not aware of, and I wonder if
> others follow this: that the phone should always be charged with power
> off, and as soon as the "fully charged" symbol appears, should be
> removed from the charger. I admit that I always charged my phones with
> them on, but he suggested that this resulted in incomplete charging.
> I'd also always been under the impression that once it's charged, you
> can leave it on the charger indefinitely with no further effect on the
> phone.
>
> He also advised me to turn the phone off when I'm on the
> subway (where there are generally no signals) for obvious reasons
> (searching drains battery). But this is rather inconvenient and I
> doubt many people would take the time to do it.
>
> Thanks for your advice, DGI
>
David:
If you swap your wife's battery into your phone after it appears to die,
does your wife's battery still seem to be discharged in your phone?
If not, that would absolve the battery and point to her phone.

FWIW, three of my relatives have had 4920s since they became available,
and all three never (or mostly never):
(1) turn power off while charging, or
(2) remove from the charger as soon as reaching full charge,
but they've never had your symptom, nor needed to replace their batteries.
Those anecdotes tend to make me doubt your technician's charging advice.

On Tue, 18 Apr 2006 23:34:09 GMT, "John R. Copeland"
<[email protected]> wrote:


>David:
>If you swap your wife's battery into your phone after it appears to die,
>does your wife's battery still seem to be discharged in your phone?
>If not, that would absolve the battery and point to her phone

If it happens again I will surely try this, but it happened
with both her old battery and a new one. I also never followed the
tech's advice with my own 4920, and never had the same problem.

The only time I ever had the battery drain rapidly was under
unusual circumstances. I had to have a CT scan done at the hospital,
and my phone was with my belongings beneath the gurney that I was on.
Later on I found that my previously fully charged phone was almost
entirely drained.

I have considered other possibilities. I believe both times
that this happened to my wife the phone had been in her handbag all
night. I wondered if she might have had the phone up against something
that continuously pressed a key. I also wondered if somehow the phone
couldn't obtain a signal wherever it'd been placed, and so spent the
entire night searching.

I cleaned the battery contacts with a bit of isopropyl
alcohol, charged it fully, and now I'm just keeping an eye on it.

The only observation I have that is somewhat in defense of
what the tech advised is that my phone had been fully charged with it
on. Then, as an experiment, I turned it off and put it on the charger.
It charged for a full hour before giving the message "charging
completed" so maybe there's something to it.

DGI

You can ask for a courtesy 24 hour batt capacity test at any Sprint
Service Center. Sprint branded batteries have a 1 year warranty.
Confirm that your roaming mode is in sprintpcs. if it is in automatic
it will use more power. Also check if there is a power saving mode. I
hope this helps.


On Tue, 18 Apr 2006 00:52:03 -0400, David G. Imber
<[email protected]> wrote:

> I don't know if any here have experience on the hardware side,
>particularly with this phone, but my wife's is doing something
>inexplicable and I think it might be ready to go to its reward.
>
> She'll suddenly find the battery totally drained. It's not
>like it empties more rapidly than usual, as a Li-On battery would if
>it's been recharched too many times. It'll seem fine, and then poof.
>
> I actually bought a new battery for it, but the same thing
>happened again.
>
> The difficult part in all this is that my contract ends June
>1st, and I'll happily re-up for the $300 in phone rebates (I always
>buy my wife and myself the same phone, and that's how I got these for
>next to nothing). I don't pay for the insurance because we've never
>lost or damaged a phone so as to warrant needing it. This is sort of
>an annoying first.
>
> So my question is whether it's worth thinking about repairing
>it, or simply spring for a new phone now and some time or another in
>the future take advantage of renewal rebates.
>
> Is anyone familiar enough with the way these things work to
>know whether it's the cellular phone equivalent of a mainboard failure
>(which would clearly call for a new phone) or if these things are
>occasionally caused by dirty terminal contacts or something?
>
> Thanks for any advice, DGI

"David G. Imber" <[email protected]> wrote in message news:[email protected]...
>
>
>
> The only observation I have that is somewhat in defense of
> what the tech advised is that my phone had been fully charged with it
> on. Then, as an experiment, I turned it off and put it on the charger.
> It charged for a full hour before giving the message "charging
> completed" so maybe there's something to it.
>
> DGI
>
The probable reason for the delay you mentioned is that LiIon charging
rates tail down toward zero during the final 20% or so of the cycle.
(I'm unsure of that percentage number though, so don't quote me.)
The charger merely feeds less and less charging current to the battery,
so as to hold the terminal voltage at the upper limit value.
The battery is deemed fully charged when the current falls low enough.

Recharging an already-charged battery simply jumps into that
taper-down part of the cycle, and the charger takes some time to decide
that the battery is fully charged.
The actual amount of charge delivered to the battery during that time
is small because of the diminishing trickle current that is used.

On Wed, 19 Apr 2006 17:46:50 GMT, Paul Miner <[email protected]>
wrote:

>On Wed, 19 Apr 2006 01:14:30 -0400, David G. Imber
><[email protected]> wrote:
>
>> The only time I ever had the battery drain rapidly was under
>>unusual circumstances. I had to have a CT scan done at the hospital,
>>and my phone was with my belongings beneath the gurney that I was on.
>>Later on I found that my previously fully charged phone was almost
>>entirely drained.
>
>How do you explain that? I wonder if someone used your phone while you
>were in the scanner?

I can't explain it at all, but I've no deep knowledge of
either cellular or imaging technology. I was conscious throughout the
procedure and the phone was beneath me while the CT device was being
used.


>> I have considered other possibilities. I believe both times
>>that this happened to my wife the phone had been in her handbag all
>>night. I wondered if she might have had the phone up against something
>>that continuously pressed a key.
>
>Not a factor if keyguard was enabled, right?

Well, I'm not sure she had it enabled, but even with it
enabled you can engage the circuitry if *, 1, or 9 is depressed, as
well as if the recorder button is pressed, although nothing was
recorded as I recall.

It hasn't happened again since, so the mystery remains
unsolved to date.

DGI

On Wed, 19 Apr 2006 11:43:41 GMT, Miroku <[email protected]> wrote:

>You can ask for a courtesy 24 hour batt capacity test at any Sprint
>Service Center. Sprint branded batteries have a 1 year warranty.
>Confirm that your roaming mode is in sprintpcs. if it is in automatic
>it will use more power. Also check if there is a power saving mode. I
>hope this helps.

Thanks very much. I checked all these things, but they did not
lead to an answer. Nothing appears to be amiss on any of those counts.

DGI

The rest of a new phone will have a one year warranty, but the battery
and antenna are excluded.

In article <[email protected]>,
David G. Imber <[email protected]> writes:
> On Wed, 19 Apr 2006 17:46:50 GMT, Paul Miner <[email protected]>
> wrote:
>
>>On Wed, 19 Apr 2006 01:14:30 -0400, David G. Imber
>><[email protected]> wrote:
>>
>>> The only time I ever had the battery drain rapidly was under
>>>unusual circumstances. I had to have a CT scan done at the hospital,
>>>and my phone was with my belongings beneath the gurney that I was on.
>>>Later on I found that my previously fully charged phone was almost
>>>entirely drained.
>>
>>How do you explain that? I wonder if someone used your phone while you
>>were in the scanner?
>
> I can't explain it at all, ...
[snip]

As I understand it:

The phone's staying in contact with the "closest" tower. It will
adjust its power consumption depending on how difficult that is. At
some point, when it's "hopeless," the phone goes into a kind of "nap"
mode and checks for usable towers only intermittently, to save
power. It's when the phone's at the bare edge of a usable signal
that it consumes maximum power whilst just "sitting there." At that
point you might as well be talking to somebody, because the power
consumption is (nearly?) as high.

--
Jim Seymour | "There is no expedient to which a man will not
[email protected] | go to avoid the labor of thinking."
http://jimsun.LinxNet.com | - Thomas A. Edison

On Tue, 18 Jul 2006 14:51:58 -0000, [email protected] (Jim Seymour)
wrote:


>As I understand it:
>
>The phone's staying in contact with the "closest" tower. It will
>adjust its power consumption depending on how difficult that is. At
>some point, when it's "hopeless," the phone goes into a kind of "nap"
>mode and checks for usable towers only intermittently, to save
>power. It's when the phone's at the bare edge of a usable signal
>that it consumes maximum power whilst just "sitting there." At that
>point you might as well be talking to somebody, because the power
>consumption is (nearly?) as high.

Thanks, Jim, but somehow you picked up my post from last
April. The problem was in the number's programming and it was just
fixed last week, after a long struggle.

DGI