Help! Zire 72 charging problem

[chaturvedimd]

Hi Everyone,
First of all, congratulations on being one of the best run forum I have ever visited.
Would like some help from you guys please. I just received a zire 72 a sa gift from a buddy in US. As it runs on 110V, I was charging it till now with a help of a transformer (that converts Indian 240 V to 110 US), connected between palm charger and wall socket, and everything was fine. TYhen all of a sudden it stopped charging. When I got this looked into, the transformer was fine but the palm charger was not functioning. The repairs chap suggested that all zire 72 was doing was receiving DC 5.5/5.8 V; so he could use a part of palm charger and solder it to a new charger which can directly charge from Indian 240 V AC. having no other alternative, I agreed to this and sure enough after repairs, the green light went on. However when I brought it home and put it on, the charging is extremely slow. I noticed that the adapter given to me now is : Input 240 V, 50 mHz, 45 mA, Output 4.5 V, 800 mA.. Is this OK or should I stop charging , as it may damage the palm?
Thanks a lot
cheers
Vivek

[raspabalsa]

Hello chaturvedimd, welcome to Brighthand!

If the specs of the adapter you received are as you indicate, then it's not adequate to charge your palm. The voltage is too low at 4.5V. A palm needs 5.0V to fully charge the battery. With that adapter you won't be able to charge your palm's battery to its maximum voltage. Also, the current (800 mA) is too low for a fast charge. Tell the guy to give you a charger rated at 5.0V and 1000 mA, this is what a palm expects to receive. Make sure that the adapter has a regulated output to ensure that the voltage does not exceed 5V +- 5%.

EDIT: I suspect that your original adapter was damaged because it was rated at 60 Hz (since it's for the USA), and I think your electrical grid runs at 50 Hz (from the specs you quote for the second adapter). Connecting via a transformer reduced the voltage, but did not change the frequency, and that may have damaged the adapter.

[chaturvedimd]

Thanks Raspabalsa,
I suspected as much. However I have compunded my stupidity since writing the query ( and gettng your reply). I thought using a different charger had messed up my charging sensors, so I did an in-cradle reset and left the palm on for the last 6 hours or so (overnight for us here), connected to the same 4.5 V charger. Now when I wake up in morning, my PDA is dead. It still shows the green light on connecting to power, but the screen is not coming on? What has gone wrong? Have I fried the zire? Please help!
Another curious thing; I had installed the batterygraph on my zire 72. When I strated charging it with this 4.5 V, I noticed that the battery % seemed to be "decreasing" initially ( dropped from 90% to 78% within 20 min or so) and then just stayed at that 78%. Has somehow the charger caused my zire to be discharged totally? ANy helkp will be really appreciated. Thanks in advance
cheers
Vivek

[raspabalsa]

Did you try a soft reset (without the adapter), see if the palm reacts at all? If not, then just take it easy and look for a good adapter for your palm.

I suggest you to stop using that 4.5V charger, as it is not adequate for your device.

I don't think an in-cradle reset will help you unless you get the proper adapter. With your current adapter the palm will fail to properly calibrate since the battery is not charging completely.

What battery graph shows you is that the palm is not charging with the 4.5V adapter, that's why the graph stayed at 78%. I think the initial jump to 90% happened the moment you connected the charger, then voltage started to drop as the charger failed to deliver expected current and voltage. I don't think the charger can discharge your battery, but I'm not completely sure about this. Probably the battery was already at a low level, so now the voltage is just too low for the palm to boot, and keeping a low voltage adapter connected is not helping at all.

In short, if your palm refuses to respond after a soft reset, then find a new adapter, 5V regulated 1000 mA, and connect your palm. Hopefully all will be well then.

[chaturvedimd]

Thanks Raspabalsa,
I tried a soft reset as advised by you, but the screen is not turning on. I am trying to arrange for another adapter, but meanwhile is it okay to atempt trickle charging by USB through computer?
Secondly you haveadvised about getting a charger with at least 1000 mA. The charger supplied by palm has this configuration: Input 120, 50Hz, 100MA Output 5.2 V, 500 mA. So is 500 mA enough or the charger supplied by palm is also wrong?
Thanks
Vivek

[Streaky]

Welcome to Brighthand, chaturvedimd.

[BAB2000]

Secondly you haveadvised about getting a charger with at least 1000 mA. The charger supplied by palm has this configuration: Input 120, 50Hz, 100MA Output 5.2 V, 500 mA. So is 500 mA enough or the charger supplied by palm is also wrong?

The Palm charge adapter provided with the Z72 is rated at 500 MA, not 1000 MA or 1 A as on previous models.

The Palm adapter is also rated as a REGULATED supply, and likely with modifications from your repair shop that feature was likely disabled or no longer functional, and if a spike occurred your unit could have suffered

Your USB should provide charge source for battery recovery. If lightning bolt icon present, then the USB connection is providing 500 MA output, good. If not then trickle charge at 100 MA is provided, and charge will take longer and recommended to turn the unit off while charging.

Hope no damaged suffered and recovery possible.

Best of luck and good wishes.

[chaturvedimd]

Thanks for the helpful replies. I went bck to the repairs guy and now he has given me a 6V 1A charger. i had it plugged in for an hour to zire but screen still blank ( the green light is still on). After reading the reply from BAB I stopped charging from that and have put my palm on USB trickle charge from PC ( i do not think it will be 500 mA, so unit is off). I really hope this works.
So can I use the 6V 1A charger for zire 72?
cheers
Vivek

[BAB2000]

So can I use the 6V 1A charger for zire 72?

I would not recommend. On the units that are provided with apadters rated at 5 VDC 1 A, this was toward the maximum rating of the battery charge circuit. Newer units provided with rated output adapters listed at 5 VDC 500MA (half the current potential), providing margin of safety, for protection of the charge circuit inbuilt to the battery most likely.

When working with 50HZ power and voltage conversion, current must be considered as well. Best to seek a international travel charger made for the Palm or stay with USB charge source. Make shift adapters may cause damage, and you will soon (hopefully not) be confirming.

[raspabalsa]

If you can't or don't want to get a made-for-palm adapter, just tell the guy to give you a REGULATED adapter. They are easy and cheap to build, should be no trouble at all, and that way you will have a guaranteed 5.0V output.
As BAB said, you are risking your valuable palm device over an adapter that will not cost you a tenth of the value of the palm itself.

And thanks for the clarification about rated current in palm adapters, BAB. All my palm devices used adapters rated at 1000 mA, and I thought this was true of others as well.