D+P reset killed battery?

[panyo]

My battery suddenly dose not hold any charge. I can start and use my SL 5500, but if I uplug the power supply, it goes dead within a second or two. When I plug in and press the power key, it goes through the boot process.

I have tried charging overnight, I have tried, I have tried charging through the cradle. I have tried doing a hard reset, removing the battery and holidng down the reset button for 20 seconds. I have flashed various OZ roms, 3.2, 3.3.5, Hentges, 3.5.1. The problem remains identical.

Only a few days ago, I had normal battery life of well over an hour. Two days ago, I was traveling and plugged in to a  5v lighter adapter which I have used before. This time I had lost the tip, and tried the wrong polarity for a second before switching to tip=positive. This had also happened in the past with no apparent consequence. It worked fine for the whole trip.

I am not sure if I used it without power after that, though I think I may have. The next thing I remeber clearly is that I tried to flash the newest 3.5.1 rom mentioned in the testing thread here. After flashing, I could not get the Z to start. I tried many things, to no avail. Then I tried holding D and P while pressing the reset button. This brought up a menue, which stays up even without being plugged in.  In this menue, I tried a number of things, but the one I am worried about is the voltage item.

One of the items lets you adjust or check the battery voltage. In the voltage adjust dialogue, I pressed the S key and the HOME button, and the dialogue said 'writing.'  After this, I was able to flash. However, now when I am plugged in, the charging light stays on, and battery monitors say the battery is charging, but if I unplug, the unit goes dead, as I mentioned. I tried pressing buttons in that battery dialogue again, but no change.

Is there any hope for recovering my Zaurus?

[pelrun]

The quick answer is "probably". If the charging circuitry hasn't been fried by your reverse-polarity accident, then the problem is you've deleted the setting in the Z that tells it how "full" a full battery is.

See this post for full details:

https://www.oesf.org/forums/inde...?showtopic=5835

[rgrep]

I would suggest that you probably damaged your circuitry when you reversed the polarity of your DC supply.  I did the same thing a couple of times - the first didn't have any effect and my Zaurus worked fine for months, but then after the second time I started to have problems with my battery not charging.

I tried all the tips about flashing the battery levels in the Service Menu, but nothing helped (I wrote down everything I did and all the values if anyone is interested).

I finally bought a replacement battery and it worked fine for a day or so until that battery went flat.  Luckily my Zaurus (C760) was still under warranty and I was able to return it for repair.

If you can't get your Zaurus fixed then I suggest you buy a spare battery and an external charger.

[panyo]

Thank you both for the information. I followed many threads on charging from the provided link. I did try freezing my battery, but the voltage was lower than what appeared to be the last flash (536 vs. 545). My charging light stays on all the times. I tried letting the battry discharge a little, unplugged, while looking through the menues. I watched the voltage drop and found that 10 units was about 0.1 volt (must get non-linear at some point- 536=3.4 volts).  I let it get down to 495, then plugged it in and only got to 507. Now the Z does not power on any more.

I will try to flash the Sharp rom and send it in for service. It is almost 9 month old and I have the recipt and original packaging. I hope I am reading correctly rgrep, that you got warranty service on yours.

If they ask, I will confess all the bad things I did or may have done (may also have started the car while plugged in to the lighter adapter, though I doubt I did that) and hope they will either still warranty or at least not charge too much.

If it comes back to life, I will be much more carefull-- will get a multimeter and test any power I plug in, memorize tip=positive and ring=negative, and never start the car while plugged in.

[rgrep]

Yes you were reading correctly, I had my C760 fixed under the Dynamism warranty.  (I sent it to Dynamism in the US and they sent it on to Sharp Japan).

It's probably better to feign ignorance and not tell them what you may have done to damage it.

[panyo]

I got my Zaurus back from Sharp within a week with the following comment:
Tech Comment: DEFECTIVE MAIN PWB.
Repair Comment: 'REPLACED F813.