Revived K3

[aha]

I think this is a rare case but maybe it'll help someone.

I have a kindle keyboard whose battery life was finally getting very short. A few months ago it stopped working altogether: the screen went weirdly dark gray and the power switch did nothing, no matter how long you held it. Plugging it in got an orange charging light that would eventually turn off. It never turned green.

I thought about replacing the battery but the screen, besides being a shade of gray I'd never seen, had one bright white horizontal line and I thought there might be some damage there as well. In which case repair might not be worth the cost.

Everything I saw online just said to charge longer, use slow chargers, play around with the power switch, etc. Finally I found a blog post about fixing a dead kindle by short circuiting it. I thought I didn't have much to lose so I opened mine up to try - and then as soon as I plugged it in, without short circuiting or anything else, the light went green and it turned on (and the screen was perfect with no dead pixels).

There was a tiny screw that fell out when I opened the case. It must have gotten knocked out of place at some point (maybe the kindle was dropped recently). So there's a chance that screw had wound up getting in the way of something. I also found some references online to a micro-switch getting stuck and to a screen cable getting loose. It's not out of the question that the jostling needed to open the case got something back to its proper position.

The moral of the story: if you aren't able to get your kindle to turn on and are at the point where you think you'll have to get rid of it, at least try opening it up and taking a look.

I'm not sure if the problem's solved or if it's just a temporary fix - the battery is nearing the end regardless - but at least now I know the screen is fine and getting a new battery wouldn't be a waste.

(And I was inspired by this new lease on its life to finally install koreader To NiLuJe and everybody else who's made it possible to do that - a million thanks!)

[DiapDealer]

I'm having similar trouble with a K3. The screen is fine, but it's stuck on the "Empty Battery" screen. Like yours, the orange charge light comes on, but goes out after 3-6 hours without ever turning green. I've got a much older K2 (that was used/charged much, much more) that was in the same "battery empty" situation that bounced right back within 30 minutes (using the same charge/cable). I was planning on taking the K3 apart, but I don't hold out much hope.

[Quoth]

I've replaced the battery cell on two K3 kindles now. They don't even work on USB power when battery is poor. The replacement battery in my own has lasted only 2+ years approx.

Opening and replacement is easy enough.

[DiapDealer]

Yeah, I popped it open easily enough. The battery's not swollen or or anything. I'm going to try a new battery. Mostly out of curiosity.

[Scoob]

Always love to read about someone trying to fix their malfunctioning product over chucking it in the bin. Double love it when they can fix it and keep using it
My first Kindle was a K3 I bought last year that I had to replace the battery as it was a similar problem to yours. It's always a little daunting trying to fix something yourself even after looking at how to vids and repair articles but it made me feel good that I could fix it.

[aha]

Originally Posted by Quoth

They don't even work on USB power when battery is poor.

Yeah, this kind of surprised me. I'm used to running old laptops without a battery on AC power - they work fine. I clearly don't know much about electronics but am curious about the difference. Are laptops just wired with two separate paths for battery and AC power supply while things like ereaders have a single path that has to go through the battery? If so what's the reason for that design, and is it relatively simple to rewire an old device to run off an external power source?

Anyone who knows about this stuff, feel free to clue me in

[aha]

Originally Posted by Scoob

Always love to read about someone trying to fix their malfunctioning product over chucking it in the bin. Double love it when they can fix it and keep using it
My first Kindle was a K3 I bought last year that I had to replace the battery as it was a similar problem to yours. It's always a little daunting trying to fix something yourself even after looking at how to vids and repair articles but it made me feel good that I could fix it.

Same here Although somehow I'm pretty bad at opening cases with clips without scuffing up the edges, and I've been known to break a clip or two. (I miss things you could just unscrew...) But it's a such a nice feeling when it pays off.

[Frogm4n]

Several mobile devices switch to battery power for a moment while powering on. If the battery is dead then when they do that they just power right back off. I've seen it happen on older Android devices, which share the same/similar chipsets as used in Kindles. If you were comfortable working with the electronics you could remove the battery and clip wires from a bench powersupply set to the right voltage to the terminals on the board. That would let it run as if it was on battery power and at least confirm general good working condition.

[Quoth]

Originally Posted by aha

Are laptops just wired with two separate paths for battery and AC power supply while things like ereaders have a single path that has to go through the battery? If so what's the reason for that design, and is it relatively simple to rewire an old device to run off an external power source?

Laptops vary. They are mostly designed to still work off external power while the battery is flat. Some have complex controllers that measure each cell in the pack. They tend to use two to eight cells.

Ereaders, tablets and phones usually have a single cell. There are several ways the cell is used. A digital camera might be similar or use two cells.

1. A direct cell and a 3rd wire is a temperature sensor. There is more than one model of sensor.
2. A cell with a built in controller and 1 or 2 wires of serial data.
3. A cell with a built in controller / manager that has only power connections.

There are ereaders that work with a dead cell and external power. The K3 cell has a 3rd connection, but I forget if it's data or temperature. The K3 seems a bit odd.

Generally types 1 & 2 need exact replacement cells, especially 2. Some type 2 also have a battery / cell ID that tells the device what capacity the cell is. Some third party cells will then only work in an external charger and capacity isn't recognised either (common with digital cameras).
Type 3 device will work with any similar capacity and chemistry of cell that physically fits the case. Possibly even a larger capacity, but it depends on the main board.

The nearly flat voltage is about 3.6V and fully charged about 4.2V, but unlike Lead Acid (all kinds), NiCd, NiMH and Silver rechargeable cells the voltage limits vary with exact chemistry / make and temperature. The Cell goes on fire if overcharged. Unlike anything else except LiFePO4, it can't at all be left on trickle charge! That sets it on fire.
Attempting to charge a completely dead, or even nearly dead LiPoly cell may set it on fire, so when a cell gets poor the main board charge controller may not charge it. Decent built in controllers or main board on dumb cells that have only a temperature sensor (often a thermistor, but a special diode is possible) will disconnect a cell when the voltage is too low and disconnect charger when the cell is charged.

Total cycles and temperature and time since made set cell expiry. Ten 10% discharges and charges or 2x 50% discharges = 1 cycle.

Storage is best between 33% and 66%, but unfortunately all the older Kindles have no "off", just a pretend blank screen mode and thus only really turn off when cell has only a few % capacity. Thus older Kindles wear out the battery even if unused in a drawer, but most other makes have a real or very nearly real off, so cell has some usable charge maybe after a year in the drawer.

If I get another cell for the K3, I will fit a real on/off switch as a "battery saver".

[Quoth]

Originally Posted by Frogm4n

Several mobile devices switch to battery power for a moment while powering on. If the battery is dead then when they do that they just power right back off. I've seen it happen on older Android devices, which share the same/similar chipsets as used in Kindles. If you were comfortable working with the electronics you could remove the battery and clip wires from a bench powersupply set to the right voltage to the terminals on the board. That would let it run as if it was on battery power and at least confirm general good working condition.

Not on some models that use thermistor and on no models using serial data. The PSU should be about 3.9V to 4.1V to avoid damage (if one cell), then either it works or not. You can't use 5V at the actual battery connections and any attempt to charge the cell directly can result in a fire or small explosion.

A PSU is mostly likely to work on a model with only two connections for the LiPoly cell that has its own controller. The USB connection then can't be used because the PSU won't accept a charging current. If you need to also use USB, then the PSU also needs a dummy load similar to load a charging cell might be. An 8.2 Ohm 3W resistor might do for an ereader that charges at 0.5A (500mA) max.

[Scoob]

Originally Posted by aha

Same here Although somehow I'm pretty bad at opening cases with clips without scuffing up the edges, and I've been known to break a clip or two. (I miss things you could just unscrew...) But it's a such a nice feeling when it pays off.

I always worry about the hidden screw. There's always one somewhere when you've unclipped everything and the thing isn't coming apart. I hate that screw. It's usually under some sticker that isn't mentioned in a guide for whatever reason.

[Quoth]

Then there is also the extra screw, after you carefully reassembled the <insert thing> that is nearly impossible to open.

[Scoob]

Originally Posted by Quoth

Then there is also the extra screw, after you carefully reassembled the <insert thing> that is nearly impossible to open.

I haven't run into the extra screw yet but I attribute that to building gunpla. I letter and number the pieces as they would be on the plastic spruce. When I remove a piece I give it a letter and number and put that info and part(s) on a note card on my desk. Then as I assemble I pull the card off my desk. Clunky but keeps track of things for me. A friend that builds gaming rigs for people does the same but with plastic bins for the parts.

[DiapDealer]

New battery installed and charged. Deregistered. Did a factory reset. Reregistered (after remembering that the OTP needed to be tacked on to the end of the regular password) and am able to send books to it from my account. Now to see how long it stays a "supported" wifi model. Not too worried, since I also have a Paperwhite that I can pull books off of and DeDRM. The KFX input plugin now makes conversion fairly trivial. Between those two methods, and K4PC 2.4.0 as a backup, I'm fairly confident that the sky is not actually falling on Feb 26.

[aha]

Thank you to everyone who answered my question (especially Quoth - that was a generous answer. Very appreciated!)

DiapDealer, hope the new battery lasts a long time.