# Battery dead, question mark, blinking home LEDs



## javisaman (Jul 28, 2012)

I had CM9 with nightlies installed on my touchpad for a few months now. Last week however, I left a game running on the touchpad and although it was plugged in the USB cable was bad and it eventually lost all charge. I've done a search on google and these forums and it seems like the touchpad is suffering from the dreaded "deep discharge" issue. It has the tell tale signs of blinking home LEDs when plugged in and a battery with a question mark screen whenever it's not plugged in.

Leaving it on the HP plug with a better micro usb cable doesn't seem to charge the battery, the plug itself doesn't get warm like it used to. However, I know the device is recognizing that it is plugged in since the LEDs are blinking.

I still can't seem to find a solid solution to this problem. The touchpad is certainly out of warranty (bought it off of HP on eBay). *I am considering opening it and replacing the battery myself, but before I try that I would like to know if there is any new updates on the front of fixing this issue?*

From my limited research on the issue, my understanding is that since the internal battery is a lithium ion, HP included some safety circuitry to prevent the battery from being (dis)charged unsafely. I'm assuming since I kept the game running, the battery completely discharged below the threshold voltage for being detected. Since the battery is no longer detected, the firmware/circuitry refuses to charge it. Some people have claimed success getting the battery recognized again by charging it on the touchstone (I do not own one), and then once detected plugging it into the outlet. I've read that someone has had success by using a lower voltage/amperage usb charger, which I'm currently. However, what usually seems to work is luck by getting the battery detected by repeatedly resetting the touchpad and hoping for the best. I've tried that numerous times and it has failed. I don't even know if replacing the battery is a viable solution, since it may not even be a battery issue, but a battery circuitry issue.


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## cobjones (Jun 21, 2011)

I have tried these without avail;

-low power charger (three days). 
-regular charger (four days). 
-computer Usb (two days). 
-power + home (15,30,45,60 seconds) 
-power + home 15,30,45 times
-home + power 15,30,45 times

I sent mine in, but it is under warranty for another month (actually another year thanks to my American express).


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## javisaman (Jul 28, 2012)

Yea, I suspect i'll have the same issues. I did order a new battery to see if that'll get it up and running. But I'm curious to see what the issue is exactly and put my engineering degree to some use!


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## cobjones (Jun 21, 2011)

If you figure it out I'm sure you will have tons of beer headed your way.

I'll toss one even if no don't need the help.


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## plusman (Jul 29, 2012)

I had something similar - but with a completely dead Touchpad after it failed to charge overnight on a Touchstone. I managed to get mine working by initially plugging it into a "normal" charger for 24 hrs (after which it still refused to boot - totally blank screen) and then plugged it into the HP charger. After about 4 hours a battery icon with a red line at the bottom appeared on the screen and after about another hour it booted u p into Android and showed 1% charge. I left it until it was 100% charged and then booted into WebOS nd installed cyboot to change the default boot to webOS.

Your sissue may not be exactly the same, so not sure if the above will help.


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## cobjones (Jun 21, 2011)

Did it have the question mark?


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## plusman (Jul 29, 2012)

No. It initially appeared to be completely dead and unresponsive - no question mark, no flashing LEDs or anything. It was only some time after I started charging it with the HP charger that the screen responded with an image of a battery with a red line at the bottome of the battery. I only wanted to highlight that the combination of low amp charging followed by higher amp charging seemed to help bring it back to life in my situation..
From looking at this issue on other fora, I think it might be time to contact HP and see what they can do (I haven't seen any posting that seemed to resolve this issue other than if you were lucky to get it restarted by the low/high charge route or by plugging it into your PC and trying to restart it whilst connected - but these only seemed to work in a few cases of those posted)..


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## cobjones (Jun 21, 2011)

You're right... The trickle trick can work for blank screens, but just to help clarify for everyone on this forum.

There has not been a fix for the question mark battery as of July 30, 2012..if someone finds a fix I will be buying them a couple beers.

Ps. I already sent mine in, but still in for a fix.


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## exioo (Jul 31, 2012)

Hello all,

I had this issue just the other day. I tried everything, but my touchpad refused to get past the blinking home LED. After screwing with the cable for a bit I managed to get the charging symbol to pop up. It stayed up though, regardless of the fact I left my touchpad to charge overnight. Eventually I was able to get my touchpad to boot up, but it still wasn't charging completely.

How I fixed it:

Take the plug-










Twist the end with the prongs counter-clockwise-










And blow on each end (like you would with an old game cartridge).

Plug your touchpad back in, and it should charge again. This is the only method I've found that works for me. Hope this helps.


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## JesusFreak316 (Sep 8, 2011)

Same issue here; sending it in for a warranty repair tonight. Obviously doesn't help you but based on my research either the internal charging logic is broken or the firmware that controls it is corrupt. Leaning towards the second as it charges enough to get to the question mark battery screen but no further. Maybe see if anyone locally has a jtag rig?


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## nevertells (Oct 29, 2011)

exioo said:


> Hello all,
> 
> How I fixed it:
> 
> ...


As an old electronics technician, I can tell you what you are accomplishing by twisting off the end cap and twisting it back on is what is really making the connection work again, not the blowing on it. Another thing you could do is using a q-tip and some alcohol, clean off the contacts on the charger side. You will not be able to reach the contacts on the plug side. Also, contact HP and tell them that the connection between the charger and end cap is intermittant. Ask them to send you both the cap and charger. They replaced mine twice under warranty. You have until the end of August.


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## danknee (Feb 10, 2012)

cobjones said:


> I have tried these without avail;
> 
> -low power charger (three days).
> -regular charger (four days).
> ...


I have one TP with the same issue and I tried all the above combos. Mine shows the battery symbol with a question mark after it was completely discharged due to being left off the charger. If I hold the power and home button for 60 seconds (hard shutoff) then I can get the TP showing the alternating LEDs on the Home button while it is plugged in. I left it in this mode for two days straight. To get it to wake back up I have to hold the power button and menu while tapping either one several times. Upon waking up I get the battery with question symbol.

Since mine is not covered under warranty I got drastic and pulled the battery out of my TP. I manually charged the battery with my RC LiPO charger (smart charger with a processor to monitor charging and only used a trickle charge) by jumping the two positive contacts together and two negative battery contact together I was able to charge via isolated alligator clips. WORD OF CAUTION: LiPO batteries will swell, burst, and release the wrath of Satan on your house and anything they touch if improperly charged, shorted out, or overheated. I charged mine using a $160 charger with a power supply on a trickle charge and inside a LiPO charging bag in the middle of a concrete pad to be safe (please don't rig a dumb charger for LiPO batteries!). After completely charging my battery I put it back in and reassembled..... Battery symbol with question mark came right back. I have given up, so now I have a spare parts TP to part out if either of my other two TPs have issues...

I'm open to any other suggestions! =)


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## javisaman (Jul 28, 2012)

Yes I've sadly learned that it's more complicated than a discharged battery. Both batteries (my old and new) are well charged (old is at 4.1v new is at 3.8v), yet the touchpad still has issues detecting them. I'll further investigate it. One thing I did learn is that the reason why it's difficult to read the charge of the battery to begin with is that you have to charge the internal capacitors of the battery controllers first (connecting red with green), then wait a few second and measure between red and black and you will get the charge of the battery.


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## cobjones (Jun 21, 2011)

Just remember if you bought with a credit card, that some extend the warranty by double the amount original.


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## nevertells (Oct 29, 2011)

danknee said:


> I have one TP with the same issue and I tried all the above combos. Mine shows the battery symbol with a question mark after it was completely discharged due to being left off the charger. If I hold the power and home button for 60 seconds (hard shutoff) then I can get the TP showing the alternating LEDs on the Home button while it is plugged in. I left it in this mode for two days straight. To get it to wake back up I have to hold the power button and menu while tapping either one several times. Upon waking up I get the battery with question symbol.
> 
> Since mine is not covered under warranty I got drastic and pulled the battery out of my TP. I manually charged the battery with my RC LiPO charger (smart charger with a processor to monitor charging and only used a trickle charge) by jumping the two positive contacts together and two negative battery contact together I was able to charge via isolated alligator clips. WORD OF CAUTION: LiPO batteries will swell, burst, and release the wrath of Satan on your house and anything they touch if improperly charged, shorted out, or overheated. I charged mine using a $160 charger with a power supply on a trickle charge and inside a LiPO charging bag in the middle of a concrete pad to be safe (please don't rig a dumb charger for LiPO batteries!). After completely charging my battery I put it back in and reassembled..... Battery symbol with question mark came right back. I have given up, so now I have a spare parts TP to part out if either of my other two TPs have issues...
> 
> I'm open to any other suggestions! =)


Yeah, since you have it apart, purchase a new battery off the internet.


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## javisaman (Jul 28, 2012)

cobjones said:


> Yeah, since you have it apart, purchase a new battery off the internet.


I would hold off on the new battery. I purchased on and it still gives me the question mark symbol. There is something going on with the circuitry that I'm trying to figure out. The old battery is fully charged and has a higher voltage than my new one.


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## nevertells (Oct 29, 2011)

javisaman said:


> Unfortunately no. And even if I did. It's been past 6 months. And I opened the it.
> 
> I would hold off on the new battery. I purchased on and it still gives me the question mark symbol. There is something going on with the circuitry that I'm trying to figure out. The old battery is fully charged and has a higher voltage than my new one.


I have seen others replace the battery and they are back up and running. Your suggestion can't be based on your experience alone. It's like $25 for a replacement battery.


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## javisaman (Jul 28, 2012)

True. But I can only give suggestions on my experiences. It's not like I'm stopping them from buying a battery. Personally what I would do is open the touchpad (you're gonna have to open it anyways) and check the voltage on the old battery. If the battery is above the 3.7v threshold then changing the battery will not help.


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## nevertells (Oct 29, 2011)

javisaman said:


> True. But I can only give suggestions on my experiences. It's not like I'm stopping them from buying a battery. Personally what I would do is open the touchpad (you're gonna have to open it anyways) and check the voltage on the old battery. If the battery is above the 3.7v threshold then changing the battery will not help.


I agree


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## cobjones (Jun 21, 2011)

Just an update...I have ups delivering my TP to me today.

This will be a total of 12 days since I contacted HP for repair.


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## freecicero (Oct 13, 2011)

If I buy a replacement battery off Ebay and replace it myself, do I need to figure out a way to charge it first, or do the new batteries come with enough charge to get things started. Thanks for replies -- I'd prefer not to buy a specialized charger too if I don't have to!


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## javisaman (Jul 28, 2012)

They have some charge, enough to be detected by the touchpad if everything else is okay. You still have to charge the touchpad once it's installed.


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## javisaman (Jul 28, 2012)

Did more testing today. It's likely a software issue. Testing the battery extensively and voltages across many of the pins shows that the tablet is reading a battery voltage greater than the 3.5v. Unfortunately, for some odd reason the software still doesn't detect the battery. I can boot it into a Palm device mode, but still doesn't really help me.


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## cobjones (Jun 21, 2011)

What does the device mode let you do?


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## cobjones (Jun 21, 2011)

exioo said:


> Hello all,
> 
> I had this issue just the other day. I tried everything, but my touchpad refused to get past the blinking home LED. After screwing with the cable for a bit I managed to get the charging symbol to pop up. It stayed up though, regardless of the fact I left my touchpad to charge overnight. Eventually I was able to get my touchpad to boot up, but it still wasn't charging completely.
> 
> ...


Didn't work for my situation,but this is good for a lot of people to see.


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## javisaman (Jul 28, 2012)

cobjones said:


> What does the device mode let you do?


Well what it seems to be is a low level communications mode. Unfortunately the windows drivers for the "palm device" are nonexistent. Luckily I run Mint linux but haven't been able to get it to detect the touchpad yet. If I can rewrite the bootloader I'll be golden.


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## javisaman (Jul 28, 2012)

I forgot to mention one sure fire way to charge your battery through the device is to use the micro usb cable to a computer and not the supplied AC charger. I left it on the AC adapter for 3 days and nothing happened (3.7v), leaving it plugged into a computer has charged the battery to full (4.25v). However, as I've found out even a fully charged battery is not detected.

So for those who are suffering from this problem:

1) First check your AC charger (as suggested) and try to charge that way.
2) If that doesn't work charge your battery by connecting to a USB port on the computer. 
3) If you're still having issues, open up the touchpad and check the voltage on the battery. Two ways of doing this, either remove the battery and first check red/green and quickly move to red/black. Or leave the battery plugged in and check Vbat on the circuit board with the ground as the micro USB ground. 
4a) If you're battery has a voltage less than 3.5v then you might be in luck. Simply ordering a new battery from Ebay may fix the issue.
4b) However, if your TP is like mine, then your battery will be fully charged yet still undetectable. This is where I am at. If I can somehow rewrite the bootloader I will be golden.


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## javisaman (Jul 28, 2012)

My touchpad is completely disassembled right now, so I'm hoping one of you could do me a favor. I'm trying to find the USB vendor and device id for the HP touchpad.

For windows you need a small program called 'USBView' and for linux run the command 'lsusb'


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## KeplersThirdLaw (Aug 20, 2012)

My Touchpad is similarly disfunctional. No response to any input, briefly got the home button to wink. Taken apart, tested the battery, drilled hole for vcc access, and now reassembled. Measuring 3.66 volts between vcc and v- without charger. Still no pulse though...

Contemplating taking battery apart to create a pin out diagram for everybody else to use.

javisaman- Have you thought to forgo the batteries and just power it with a power supply? I've been thinking about building an external battery to power the device. I have no idea what the middle three wires are. You mentioned the green and yellow are tied to caps?


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## freecicero (Oct 13, 2011)

Just wanted to say that I like your attitude KeplersThirdLaw. We can't let this thing beat us!!! ;-)


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## javisaman (Jul 28, 2012)

KeplersThirdLaw said:


> My Touchpad is similarly disfunctional. No response to any input, briefly got the home button to wink. Taken apart, tested the battery, drilled hole for vcc access, and now reassembled. Measuring 3.66 volts between vcc and v- without charger. Still no pulse though...
> 
> Contemplating taking battery apart to create a pin out diagram for everybody else to use.
> 
> javisaman- Have you thought to forgo the batteries and just power it with a power supply? I've been thinking about building an external battery to power the device. I have no idea what the middle three wires are. You mentioned the green and yellow are tied to caps?


You can power it externally with a 3.5v (I used one from an otoscope). The outcome is the same. The other leads might be for powering the internal circuitry of the battery. Or maybe even alternate voltage rails. Plugging in the usb cable to the touchpad with the battery just lights up the alternating LEDs on the home button. You need the battery to power the screen. However, I suspect board can be run off of the usb, though I haven't been able to verify it.


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## Cornflake (Sep 3, 2011)

Well I had this issue - I tried almost every single thing I could find in forums except opening up the TouchPad.

I spoke with Palm's customer service chat, and they had me send my TP in. I just got the mail today that they've already shipped it, so hopefully I'll see it in by Monday? Will let you guys know the update.


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## freecicero (Oct 13, 2011)

FYI - I have just cracked mine open, put in a replacement battery I purchased off ebay, and begun several of the multi-key wakeup efforts described in other posts. So far, replacing the battery has made absolutely no difference. When I attach to my pc, I still get the same three off-key notes that signal a problem. Will report back if trickle-charging and/or touchstone charging are able to way up the replacement battery. Unfortunately I have no tester to test the voltage or I would report that too.


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## Cornflake (Sep 3, 2011)

So I received my Touchpad today, they had done a full wipe and reverted me back to WebOS I guess but the good news is, it's up and running again!

Just a heads up, if you talk to their support - NEVER mention that you've installed Android or done anything that'll void the warranty.


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