A501 working the leak - done.

Hi,
i did it !!
Today i work out the A501 leak.

Lemon juice, swabs, water with soap, toothbrush and clear nail varnish.
easy!!

check the photos:
http://lobodias.com/html/a501_leak_work.html

Interesting method. I've not seen nail varnish used before. Is that just to seal any damaged parts of the PCB into place and help stop further corrosion?

Looking at the pictures, the battery had leaked quite a bit so it was good you did look and remove it before it leaked any further and damaged more important areas of the board.

The Lemon juice is acid, so it's the oposite of the leak, as someone told be. It will nutralize the leak. then you wait some time, and clean it with soap water. After the nail varnish will protect the area from oxigen, preventing corrosion, and other problems.
I was afraid that after all the work i could damage something, but it's working..!!!!
very important is to wait a few hours between each step, to give time to dry.

Next step put a CR2032 coin cell with a diode as replacement of the old battery. I order the CR2032 and a support for it, very cheap, i am still searching for the best diode for it.

When I've cleaned battery acid I normally just use isopropyl alcohol to clean the area. This is commonly used to clean electronics safely. It can be hard to find isopropyl alcohol sold in stores though, but it is easy to find car carburetor cleaner which is basically the same thing, so I normally use that. This has the advantage of a very quick evaporation so you don't need to wait for it to dry. It's also great for cleaning CPUs of old thermal compound and loads of other computer uses such as contact cleaning.

For the diode you will need a Germanium type (lower voltage drop) model: 1N914/1N4148

The reason for using a switching diode is to allow the battery to power the clock, but stop the motherboard circuit from trying to charge it. Coin batteries are not usually rechargeable and might explode when charged. Make sure you DO NOT use a resistor for coin battery solutions, as that could cause the battery to EXPLODE.

Put the diode on the + side of the battery, and orient it to point the stripe away from (+) or towards (-) (the cathode facing the motherboard in, and the anode facing the battery, as you want the current to run out of the battery, not into it).

And for the battery, use a CR-2032 battery and matching spring-loaded holder. I had some dead PC motherboards with coin battery holders on them, so just desoldered and used those. These can be 2 or 3 pin holders as it doesn't matter. Normally the 2 incoming + pins are identical and only for stability in securing them to the board. Normally only one of them will actually be connected to the incoming circuit, or both joined together.

If you have trouble finding diodes I have a load of spares a friend sent me when I wanted to do the same thing. If you don't have any luck finding some yourself I can post a couple do you in the new year.

Well i found the cr2032 very cheap on ebay, i order 5 and also 3 coin cases. I will practice on an faulty board. I had only use solder 3 or 4 times, my solder iron is not that great, i will have to grab another.

about the diodes, i dont know what i will by, they are cheap, but there are a lot of them in ebay...
can you point me 1 or 2 exemples of good diodes in ebay please?
thanks