5500 charging circuit, various failures with charging circuit Options

[jalex]

I have a 5500, serial 27030301. It runs and boots from battery. However, I cannot charge the battery, even when I turn charge on from Diag menu. The AC adapter that came with it, Phihong PSC10A-050 says it is 5V at 2A current. However, when I test it with a multimeter I get 3.8 Amps, at 5.01V. I suspect this AC adapter may have damaged the Z, but no way to know since I received it second hand and the previous person seemed to think it worked or something.

I am getting very low volts/amps from the battery terminals, even when it was running with the ilght on. I can get to the diag menu on battery, but AC doesn't seem to register. I do see the volts cycle on the middle connector of the battery connections, which is good, since it uses a little cycle to detect the battery.

Without AC registering or charging, I cannot flash the ROM.

I was wondering if someone had a link or document with the voltage/current of a good, healthy zaurus on hand. I think this would be helpful.

Also, where is the charging circuit on the Z and how do I identify the components. The resistors, transistors and capacitors all look very different from the big old ones I am used to seeing. Some of the components even have numbers on them.

I will probably end up sending it this Z tio Romax in Texas. I got their info from the 1-800-be-sharp messages. Unfortunately, I can't help but believe I am screwed and it will cost 100+ dollars to fix.

Before I sell it for parts, it would be absolutely awesome if someone with a healthy Z has some info on what to expect from it and what may be possible.

Thanks.

[zbones]

See the bottom of this page :-

http://www.tekprosystems.com/zaurus/internals.htm

Let us know if you get it working.

Peter

[omega]

how did you measure 3.8 amps at 5volts? Amps is only capacity... it's not important as long as you have enough. Your Z will only take what it needs.

[jalex]

I measured current with a multimeter. When you initially put the AC adapter into the Z, it will cause a very quick short - not sure if this is normal. Continuity tester showed the same thing - a quick beep just as you hit the connectors. If this is normal, and the current is too high, damage is possible, I would think.

My connectors are fine. I get close to 5V at the terminals under the keyboard and at the AC jack terminals. The terminals measure the same if I am using the USB docking cradle or AC directly.

[dansawyer]

I also have a Z with a charging problem. The charging circuit seems to function. However the s/w control or sensing circuit detects the battery is fully chrged almost immediatly after it starts to charge. I have worked part way through the diag menu. Has anyone sorted out how that works?? There is a setting in that menu that turns on charging. That actually works if forced.