A4000 Battery Leak...

[Claw22000]

I have an A4000 with a leaky battery and I am going to remove it from the board. However there is some corrosion on the board and I know I can't just pour coke on it any one know what I should do to remove it?

Also does the board need a new battery or can I use it without one?
(I don't care about time stamping)

[prowler]

Originally Posted by Claw22000

I have an A4000 with a leaky battery and I am going to remove it from the board. However there is some corrosion on the board and I know I can't just pour coke on it any one know what I should do to remove it?

Also does the board need a new battery or can I use it without one?
(I don't care about time stamping)

Hi Claw22000,

If you don't care about a RTC then you won't need a battery.

Important: Before you use the soldering iron, cut the battery free from the board with wire cutters to make it easier to desolder and remove the wires without lifting the pads.

The pcb deposit from a leaky battery is alkaline, so you will need an acid to neutralize it. Lemon juice is generally preferred, because it does a good job of dealing with both the deposits and corrosion, and also it leaves any exposed copper track shiny; whereas vinegar, for example, tends to taint such surfaces.

Apply it with a stiff brush made from a 12mm paint brush by cutting the bristles short (to 10mm or so). Pay particular attention to the pcb surface around and underneath components near the battery. In cases where severe leakage has occurred, it may be necessary to remove those components to clean all traces of corrosive substance and prevent subsequent damage.

Coke will do the job, but carbonic acid is too weak and any phosphoric acid it might contain will be so dilute that you'll need at least a bucket full of it to ensure it's done right.

Afterwards, you can either rinse off the residue with tap water and leave to dry for a few days, or use a more volatile liquid like isopropyl alcohol (propanol) for a quicker drying time.

[Claw22000]

What do you mean by lifting pads? I've heard other people talk about this but I don't understand what it means. Also it seems to be the consensus that lemon juice is the way to go. I must say I am a bit afraid to do this as I have never cleaned a. Pcb before. I do know it has to be done. Wish there was a fellow amigian in or around minute that wouldn't mind helping. Hint hint. Wish me luck.

[prowler]

Originally Posted by Claw22000

What do you mean by lifting pads? I've heard other people talk about this but I don't understand what it means.

If the battery has not been removed with wire cutters before you try to desolder its connections from the board, it will have an additional heat-sinking effect which will make the solder more difficult to melt.

Thus, the soldering iron will have to be applied to the joint for longer and, at the same time, you may be tempted to press down harder on the iron to make better contact. Prolonged heating of the solder pad (the circle of printed copper track which makes it possible to form a solder a joint between the battery lead and the circuit) may weaken its bond with the board and cause the pad to become very prone to damage. Any movement of the soldering iron while pressing down hard on it may cause the pad to fracture and come away, whether you're using a solder pump or braid to remove the solder or merely prising up the battery to remove it, and this is what's referred to as 'lifting the pad'.

With the battery first removed, this will be far less likely to happen, since the solder will melt more quickly and thus be ready for the joint to be separated at the first attempt.

To avoid this problem, many owners simply remove the battery with wire cutters and leave the connections behind. As you don't intend to replace the battery, this will be perfectly adequate, provided you carefully remove all traces of corrosive matter from the board afterwards.

Good luck, whatever you decide to do!

[Claw22000]

That sounds nice as it dosnt require soldering. I will be attempting to repair this some time this week. I will be cutting the battery then using lemon juice for the acid bath. And IPA for rince. I hope this will work. The Amigoody is a nice find I hope to restore it.

[prowler]

Originally Posted by Claw22000

That sounds nice as it dosnt require soldering. I will be attempting to repair this some time this week. I will be cutting the battery then using lemon juice for the acid bath. And IPA for rince. I hope this will work. The Amigoody is a nice find I hope to restore it.

If you're careful to keep the cutters clear of the board to avoid damaging it when snipping the leads, you should be okay.

"Acid bath" is a bit extreme. Just brushing it onto the affected areas should do the trick.

Good luck, and let us know how you get on. Please include some pictures too, if at all possible.

[Claw22000]

Acid bath is just what they call it at work. I will take some pictures to share. Maybe even some video.

[prowler]

Originally Posted by Claw22000

I will take some pictures to share. Maybe even some video.

[Claw22000]

Well Heres some pics hope to get to it soon Just got a ton of work dumped on me and when I'm not working I busy being Dadadadadadadada (thats how he puts it. Hes 13 months)

[8bitbubsy]

Poor girl! I am sorry to say this but she is probably dying a horrible death as we speak... This will be a hard and time consuming process. Important tips:
Be patient, use no force, neutralize the electrolytic liquid by using raw lemon juice (not the ones with sugar in it), clean up with either acetone or isopropanol, desolder all the affected components, clean under them etc... You are almost guaranteed the need to bridge some circuits...
Other horrible things that might happen are breaking IC pins and lifting PCB pads. This is a nightmare for sure, sorry buddy.

[prowler]

Hmm... That'll be quite a tough job.

Make sure to clean thoroughly the area around the surface mount resistor array and underneath capacitor C192 and IC U177 and, to a lesser extent underneath U976, U897 and U178.

[Claw22000]

underneath? like the other side of the board or remove/clean then replace?

[prowler]

Ideally, you should consider removing those components to clean underneath them but, provided you use a cut-down paint brush, like the one I described above, to apply the lemon juice and propanol, you may just get sufficient reach to make their removal unnecessary.

[Claw22000]

Right now I need a good Suggestion on what to do the cutting with? Its not as easy as a wire cutter. Tin Snips?

[prowler]

Yes, tin snips have been used successfully in many instances of battery removal.

[Claw22000]

Originally Posted by prowler

Yes, tin snips have been used successfully in many instances of battery removal.

I'm going to have to buy some Kinda figured I would end up buying tools.

-=EDIT=-

Any other tools I might want to buy while I'm out there?
Anything I might need to buy while I'm out there just to get it so I don't need to go looking later. I know about the tooth brush and a artist brush.

[rkauer]

If you can do real good SMD soldering, lots of materials (hot air station, .1" solder, flux, dessoldering paste, solder braid, etc, DON'T FORGET A NEW WIFE, the one you have may left the house...).

If not, lemons, brushes, IPA alcohol and nail varnish or circuit board varnish in a spray can.

[Damion]

Originally Posted by rkauer

DON'T FORGET A NEW WIFE,

LMAO!

Yeah, honestly it doesn't look too bad, I've seen worse. The main problem is finding someone with the time to do it. As rkauer hinted it will require many hours to repair, not including the tedious task of tracking down all the parts. If you don't do much solder work, I'd hang tight (after removing the battery and cleaning ofc) and send it to Anthony Hoffman in NZ when he's returned from Antarctica... due back November I believe.

[Claw22000]

ok and how much would a fix like that run?

[rkauer]

Knowing Anthony, not much.

He is an awesome & skilled guy very community-oriented. God bless him.