I want to repair a sansa sandisk that has connection issues

[Alejo88]

I have a sansa sandisk e140 series, i left it for a year with the battery on, so it corroded the contacts. I cleaned them and they let the current pass perfectly. It works on pc plugged with the usb; it works perfectly if I attach the clips of a transformer at 3 o 4,5V. But the mystery is that I doesn't work with the battery. Then, for no reason it 'magically' doesn't work with usb nor transformer, just 3 minutes after it worked... Any help is welcome and appreciated!!! Thanks!

 

[davenn]

HI
welcome to the forums

what sort of battery(s) does it use ?
show us some pics of your unit showing us where the corrosion is/was


Dave

 

[Alejo88]

Thanks a lot for the reply!!! It uses one AAA battery... My batteries work fine.
I desolded and solded again the two contacts to the circuit, so that the soldering iron would be completely replaced... But nothings changed.

 

[Alejo88]

photos

 

[davenn]

OK that gives a good overview

can you do 2 more one of each end of the battery solder joins
as sharp and close up as possible, just want to see the 2 solder joints and make sure something isn't shorted out etc

Dave

 

[Alejo88]

i have problems uploading the files... i press the button and it does nothing...

 

[davenn]

you uploaded the other file OK ... just do the same thing

 

[Alejo88]

The button doesn't highlight, post reply and more options ... go yellow... but olupload file doesn't, i'm on firefox. last time i had troubles too but could do 1.

 

[davenn]

cant help you with that
check for browser updates
try using IE

Dave

 

[Alejo88]

i remembered i had chrome... but it's so slow!!! appear to be a flash issue...... - -
I hope those pictures help. It's quite a mess actually... sorry, so amateur, i get mad with the thing and attack the circuit with the soldering iron, like 'DIEEE!!'

 

[davenn]

OK

That last pic 3a,jpg looks a pretty rough solder joint, I would be unsoldering it, cleaning up (scraping clean) the end being soldered to the board

But before that ..... a question .... did you have BOTH battery contacts unsoldered at the same time ?
if so, are you really sure you put them back in the right place. Am just wondering if you reversed them and you have been putting the battery in back to front ??

At this stage, cannot offer any other insites other than those 2 thoughts

 

[Alejo88]

You are very kind! Didn't expect so much patiance. I took care to put them in the correct place; i learned a LED burns if you change voltage. I'll try cleaning the joint and resolder, but anyway, it's very mysterious, it worked like that while beingn with USB and with transformer, then didn't, just like that... better pay attention to more important things than this i guess. Thanks a lot!

 

[Alejo88]

The thing works fine, when i supply from adapter at 3V. Rust was in the battery contacts and they are not making contact with the battery efficiently, so that's why i doesnn't fuction. I should replace those two battery contacts... i tried with simple wires imitating them , but it doesn't work... can it be that 1,2V is now not enough for it to work andn it requieres 3V??
The player is perfect, only for the two battery contacts...!