Battery charger not working. A white wire that connects to the AC plug has become disconnected. Can soldering it back on work okay?

Seems likely the battery has become disconnected or has completely failed. It's not common for a battery to fail like this overnight so I'd look for a broken wire or bad solder joint inside the unit.
Can you get inside it to check the battery connections etc.?

Hi, yes it's possible you need a soldering iron and 60/40 rosin core solder, remember that soldering iron can make serious burns so be careful, and always work with the device disconnected from any power source.

please measure the output for your charger,normally they have 19.5 vdc exactly, if they do not measure the adapter is faulty, repair or replace.If the output is o.k the battery can be faulty. Use the software diagnostic coming with the computer, restart the computer HOLD the key f2 or esc depending of your computer model, and make the diagnostic.try again and see what is the result, if the battery is o.k or faulty.God bless you

This seems like a poor soldering job at the factory which has become loose/disconnected over time, affecting the power port the ac adapter plugs into. Take the laptop to the shop and have your power jack inspected.

1) Check to make sure the problem isn't the cable going into the plug, from the AC adapter. (Charger)
A lot of times, where the wires meet the back of the plug, that goes into the laptop DC Power Jack, is bad.
The wires have a break from becoming stretched. Makes an intermittent contact.
Same thing for where the wires meet the charger body.

AC adapter plugged into power, unplugged from laptop, use a multimeter set to the DC voltage scale.
Use the alligator clip attachments for the probe leads, attach the probe lead's to the AC adapter's plug, and wiggle the wire, check for an intermittent break.

2) AC adapter (Charger) unplugged from laptop, Battery removed, see if you can wiggle the center pin of the jack.
You may find the entire DC Power Jack will move a little.

If the center pin does not move, but the entire body of the jack does, the jack may just need to be
resoldered to the motherboard. The solder connections may be cracked.
If the center pin moves, replace the jack.

To replace the DC Power Jack, or repair the solder connections,

1) Remove all power to the laptop. AC adapter and Battery.

2) Observe Anti-Static Precautions:
Buy and wear an ESD wrist strap. (Electro Static Discharge) Connect the alligator clip to a good ground source. I connect mine to the metal frame of an open, empty desktop computer case.
(You don't need an Anti-Static Mat)
The price of an ESD wrist strap is around $3 to $8. Found in a multitude of places.
Example,

http://www.costcentral.com/proddetail/Cables_Unlimited_Anti_Static_Wrist_Strap/ACC1400/10720671/froogle/

3) Completely disassemble the laptop down to the bare motherboard in your hand.
No Processor, Heatsink assembly, peripherals, nada.

TIPS:
A) You may wish to take photos, or make a video as you disassemble, for your first time. Also make notes.
After the first laptop the next one becomes easier.
(All of them follow a basic path when disassembling. Toshiba, HP, Acer, Gateway, you name it)

B) Use a multi-container for the various screws. Label each container for the area the screws came out of.
There may be 60 or more screws, and 12 different types of screws. Some look VERY similar to each other, but are NOT. DO NOT mix them up.
You can use a clean egg container in a pinch. Label each egg holder.

C) Take your time, use patience. Practice your soldering, de-soldering skills before working on the Toshiba's DC Power Jack, if you're rusty.
Use Desoldering Braid, and not a Desoldering Tool. (Solder S-ucker) The desoldering braid works MUCH better! (Also known as solder wick)


Pictorial, with details on how to disassemble the Toshiba Satellite A70, or A75 series of laptops,

http://www.irisvista.com/tech/laptops/ToshibaA75/satA75_1.htm

You can click on each photo to enlarge.
Page 2, and 3 icons are at the bottom.
(You are on Page 1.
Page 1::Page 2::Page 3 )


One source for a Toshiba Satellite A75-S209 DC Power Jack,

http://www.laptopjacks.com/view_part/For-Toshiba-Satellite-A75-S209-DC-Power-Jack-TS51625.html

Toshiba Satellite A70 series Service Manual, (Free)

http://www.tim.id.au/blog/tims-laptop-service-manuals/#toc-toshiba

Go down to the line that begins with Satellite A10.
Scroll across to A70, and click on it.
This is a PDF file. May take up to 30 seconds before you see the first page.
May take additional time to fully download.
(Took me around 40 seconds before I saw the first page, with a medium speed DSL connection)

Regards,
joecoolvette

Turn everything off. Take off the battery. Connect the ac adapter and turn on your computer. If it works with the ac adapter connected and your battery off then you have a defective battery.

If it does not work then it's either your ac adapter or your dc jack inside your computer. Try a different ac adapter at the store you bought the battery and you'll know if your adapter is bad. If it works with another adapter then exchange the adapter again (I know, I know, I've been there). If it does not work with another adapter then you're back to the dc jack but at least you'll know for sure.

Make sure that whoever is replacing the dc jack is good at soldering and replaces it not just solders the same one back on. Don't forget the shield to the dc jack. Good luck!

1. Actually the problem is not with the charger / adapter!

2. The plug-in port / jack of the laptop has become loose.

3. Don't try to work out the charging by adjusting the adapter plug with different angles. It will just damage the plug-in port (the wire inside the port will become loose and unaligned)!

4. Contact the Acer authorised service center for repair / replacement of that plug-in port / jack in the laptop! It'll just cost some bucks!

please rate this advice if it helps....tc! :)

Motherboard is bad and will have to be replaced unless of course the AC Jack on the back of the laptop is loose. That would cause the ac adapter not to charge and then you would have to take the motherboard out and put solder on each leg on the bottom of the ac jack to make sure it stays in place then the ac adapter can charge the battery properly.

Even going thru the solder method the motherboard could still be bad and have nothing to do with the ac jack.

try looking at the DC input. My brother's 1st laptop had that same problem. All we need to do is solder it. Remember-1st dc connection, not the one on the MB.