Battery won't charge

[cortez]

I have the following problem with my C750. The battery is completely empty, and it won't charge in the Zaurus, whatever I do. After approx. 5 minutes the charge LED starts blinking.

The option "Low battery" from the D+M service menu shows:

Main battery status: L
Main Bat: 2.3V ( 121)
Thrmo: 1.6V ( 130)

I now am only able to get the machine running on external power, and by doing a D+B, followed by a ./sbin/reboot command in su-mode. After that, the Zaurus is rebooting my Cacko QT nicely and (as long as on external power) working perfectly... except for any CF card inserted, that is. Is battery power crucial for the CF-IO to work?

By the way, I always thought the Zaurus didn't do anything without a battery, but this isn't the case. Just remove the battery, do the D+B trick, and reboot... no problem.  The charge LED is blinking, in fact the same situation as currently charging my battery for more than 5 minutes. Can anyone of you check and confirm that, after removing the battery, the CF is still working?

Any help would be greatly appreciated, I have to be near an outlet all the time now!  

cortez

[rgrep]

I had the same problem with my C760.  I thought my battery was stuffed so I bought another one and it worked fine until that battery went flat.  The real fault was my charging circuit, so I sent my Zaurus back to Dynamism (it was still under warranty) and they had it fixed by Sharp Japan.

[omega]

cortez, having rooted with external power supplies to solar panels and stuff i can tell you that if your power supply is not stable enough it will be dragged down and hence the led will blink at charge switches on and off rapidly.  I don't know if you can check it with a multimeter while it's charging....  e.g. you could pierce the cable with two small needles and measure from those.  If it's not this then there was a thread about resetting flash options in that service menu because they got corrupted.

[cortez]

omega,

You're right, I found a similar thread on the externe board dealing with battery problems.  It indeed mentions clearing of the battery adjustment, by doing:

Service menu, Page 3/3:
Option 7 "Extras menu",
Option 6 "Normal Diag Mode",
Option 4 "Clear Adjust value".

Just done that. By doing so, the 3 bottom left values in the service menu are replaced by *** (that is Tablet, COM and phase).

After a Reset, and another 5 minutes charge, the charge LED begins flickering again, so I guess that's not it  

The thing you suggest with the multimeter is not exactly my cup of tea, I'm afraid  

Any other ideas left, before sending it back to Japan? Can anyone of you test to see if a CF can be used while on external power, and without having a battery placed?

Thanks in advance,

cortez

[cortez]

I guess I'm talking to myself here...

Isn't there anyone of you willing to test to see if a CF can be accessed while on external power, and without having a battery placed?

[cortez]

Well, I finally got myself the original Sharp CE-BC21 external charging unit AND the EA-70 AC Adapter, with a EA-BL08 spare battery (no half measures taken )

Here's my full story...

Having the EA-BL08 in the (slightly modified) external adapter, I connected the AC adapter to my C750, to see if it would charge my "old" EA-BL06 in the unit.

After 5 minutes the charge LED began flashing again, just like before, which gave me the impression that the charging circuit had a defect somehow. Therefore, I placed the larger EA-BL08 battery, and charged the smaller EA-BL06 with the external charger.

The Zaurus booted, and everything worked fine, including reading of CF-cards. Lucky me  

Now, here's the strange part. After completely charging the EA-BL06, I placed it in the Zaurus. Guess what, since then, charging the battery also works with the AC Adapter... no flickering charge LED anymore, all works perfect  

I don't know, I guess my Zaurus was waiting for eh... the mood to be right??

Anyhow, I removed the battery, and connected the AC Adapter while pressing D+B. The Zaurus boots, I login, enter superuser mode, and type ./sbin/reboot. This reboots the machine, and in my case starts Cacko 1.20. This all without having a battery in the machine! After rebooring, all works fine, except for reading CF-cards, they simply aren't recognized. This unlike SD-cards which can be (un)mounted without trouble. As a matter of fact, mounting a CF-card results in the Zaurus being shut down completely.  

So, to give an answer to my own question, yes, I guess the Zaurus needs battery power for using CF-cards.

[Zuber]

You can actually do a NAND restore from CF without the battery in.

Would not recommend it though, since you might stuff it if you loose power briefly.