Bill_Todd

A while ago I replaced my X51v's backup capacitor (with a rechargeable lithium cell). It has been fine for several months but recently the time has once again been resetting while swapping batteries.

This evening I've taken the Ax apart to make some measurements; The results are both interesting and worrying.

First I removed the lithium cell. A few quick tests revealed it to be OK and holding a charge.

Then I measured the current required by the standby circuit, using an external 2.8v supply. It is drawing 2.7mA which is far too much for a standby circuit and enough to effect the battery life.

[There was another Ax owner asking if the backup cap could effect battery life in my 'replacing the backup cap' thread].

I gave the whole board a thorough clean with a high quality PCB cleaner / rinse agent (safewash2000) dried it with an air blast and 20 minutes in a temperature controlled oven. Yet it was still drawing 2.7mA through standby cell.

It would appear that something on my board (and many others) has begun to draw excessive current...





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Bill

Bill_Todd

I've traced the standby supply to here: (the two small chips just below the CPU/memory screening can)



Can anyone identify the chips?

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Bill

piolo

Hi, i have the same problem.
Can you say me how have you find that the problem is in this 2 chips so i can try to see if is the same in mine?
Also i have the problem that my axim is hot when i recharging the battery.

mostlylisten

My axim does the same thing. I'm off the subject a little bit but read somewhere on this site a person discussing the difficulty and impractablility of changing the capacitor. OUt of my tech expertise also.

Redo the time after time after time.

kcallahan

Batteries are not designed to replace capacitors. Unless you redesign the circuit, I suggest going back to the capacitor.

Ps - You're probably drawing too much current because of the battery.

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piolo

i have the capacitor... and it works... i've tested it out of the circuit...

Now i have another big big problem...
on standby my axim x51v drain a lot of current... it drain about 250-300mA when it's on and about 100mA when is on stand by... that it's too too much..
I've also tried a soft reset and nothing change
I don't know why... anyone can help me? also suggests to find the problem...
Thanks. :D

JakeRich

Originally Posted by piolo

i have the capacitor... and it works... i've tested it out of the circuit... Now i have another big big problem... on standby my axim x51v drain a lot of current... it drain about 250-300mA when it's on and about 100mA when is on stand by... that it's too too much.. I've also tried a soft reset and nothing change I don't know why... anyone can help me? also suggests to find the problem... Thanks. :D

That's about normal. See this thread for details. It's a big thread, but on page 2, Kenban posted some consumption figures. The 1100 mAh battery lasts 5-8 hours, max, so 100-200 mA draw is in the normal range. 100mA in standby is high, but that could be your memory card (SD or CF) drawing power to sustain itself. Some older cards do that.

piolo

thanks... i've read it... :)
unfortunately the 100 mA current is without any sd or cf card and without bluethoot and wireless... after an hard reset...

my battery goes down in about ten hours (a night)
so i can't use the axim if i'm not on the AC power... i'm very sad because i think x51v is one of the best ppc even if it as some years and i can't use it normally...

i'm pretty good in electronic but with this circuits i don't know how to find and fix problems... i need an help...

Bill_Todd

Just to put my original thread to bed (so to speak) :)

After replacing the rechargeable 'battery' with the correct super capacitor my Axim has been working fine.

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