The Screw In Front Of Paula's House

[MiAmigo]

Decided to take a break from my epic battle with the stubborn A2000 in the workshop. As a matter of fact, I have forbidden myself from going back there for the next few days - until my newest Amiga monitor arrives, at which time I will finally proceed with installing 3.9.

In the mean time, I've been enjoying playing games on my new A500. (Since I'm temporarily a monitor short - I took the monitor from the A2K and am using it now on the A500). Even though its in pristine condition on the outside, the dust constantly peeking out from the keyboard made me want to open it - so I did.

Wow! There was a lot of dust in there - mountains of it! I could just barely see the casing around the keyboard, or the shield!

I got my mini-vac and air blower and got to work. It wasn't long before I realized  that I would have to also remove the metallic shielding to do a proper job of it, and that's where I ran into trouble with that inconveniently placed screw which secures the shielding - right in front of the PAULA chip.

Note To Self: Pick up a set of long neck magnetic torix screw drivers on the next trip to Ace!

Anyway, I eventually got the screw out, (which was much easier than getting it back in!), and found what appears to be an expansion card of some sort with what looks like a battery attached to it.

It was my understanding from the seller that this machine had no battery, and a bootup message concerning the absence of a clock battery would seem to confirm this. However, this definitely looks like a battery to me, on some type of memory expansion card(?). And it looks like it has a tiny bit of corrosion and leaking.

Now my question is: What exactly is this? If it is a battery on a memory expansion, will I have to replace just the battery, or then entire card?

??

[paul1981]

Looks a lot like this one:



http://www.amiga.org/gallery/index.php?n=3323

You can replace the battery. Then your Amiga will remember the time & date.
After you've removed the old battery, you must neutralise the corrosion with lemon juice (do that whole half of board or whole board) and then rinse with water (you can put it under the tap). I'd used cotton wool buds to apply the lemon juice. You can also use concentrated lemon juice if you like.

Edit: Due to your chips being socket, might not be a great idea to wet those.
But in any case, do make sure all is nice and dry before turning back on again.

[TjLaZer]

That card with the battery is a Commodore-Amiga A501 512kb RAM expansion card clone.  It upgrades the A500 to 1MB RAM.  It also has a RTC clock and battery to save the time.  These are prone to leaking and damaging the RAM card!  This issue also happens on the A500+ (which has this RAM card and battery built into it) along with the A2000/3000 and 4000's.  Remove the battery, clean the area with lemon juice and clean off with isopropyl alcohol and let dry. You can then either leave battery off (no need for battery unless you want to timestamp your files!), or install a NiMh 3.6V battery in its place.

[MiAmigo]

Good idea. I think I may just take it off, clean the area, and leave it off. Cost and availability-wise, is this a better idea than just replacing the entire card?

Or would that either A). Cost more/the same, or B). result in probably the same situation - a battery that still needs to be removed? (Unless there's a vendor out there somewhere selling brand new cards, I'd most likely be purchasing another used one from eBay.)

[TjLaZer]

it cost like $20 to $50 for a new replacement card, and most have the battery still on and leaking.  So if it works, definitely it is cheaper to repair this one!


Here are the new NiMh direct replacements:

http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=132


Amigakit has coin cell adapters for sale, they work great!  No leaks either:

http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1093

[MiAmigo]

it cost like $20 to $50 for a new replacement card, and most have the battery still on and leaking.  So if it works, definitely it is cheaper to repair this one!

Here are the new NiMh direct replacements:

http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=132


Amigakit has coin cell adapters for sale, they work great!  No leaks either

http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1093

Simply fantastic. That was my very next question!

[TjLaZer]

Fire up SysInfo if you can to see if it detects a Clock battery.  The card could be damaged but still work as a RAM card.  Whats interesting with it is there are empty sockets...  Does it report 512k as fast ram?

[danbeaver]

What is it with the lemon juice and isopropyl alcohol?

While the leaked battery paste is potassium hydroxide, it is water soluble as are the corroded metal; if you think that simply washing it away is not good enough and you want to use kitchen ingredients, then why not use acetic acid (white vinegar)? Why exposé the circuits to lemon pulp and all the other junk from a squeezed lemon?  Secondly, the isopropyl alcohol is only 30% water (or 10% using the 90% isoPrOH solution); is this to dissolve grease?  Plain water will dissolve and wash away the corrosion, so the alcohol evaporates more quickly and this does what?  Clean away the "germs?" Yes it dehydrates and denatures the viral and bacterial cell walls, but do circuits care?

Please explain the chemistry, physics, and electronics behind this voodoo mixture

[MiAmigo]

I dug up Sysinfo on the internet and made a disk for the A500 on my A2000. Unfortunately, the 500 keeps saying that the disk is 'bad'. (Its an Amiga disk).

Also, even if I can somehow get the 500 to accept the disk - I think my WB version (1.3.2) is too low to run this app.

However, I did get a chance to run it on my A2000, and it gave me lots of info about that machine, including something I've been wondering about - whether or not my accelerator card's processor was dead! It seems to be alive and well.

The A500 will need across-the-board upgrades, including a new battery for the mem expansion, a new WB and kickstart, and some type of internal storage other than just the floppy drive.

[paul1981]

What is it with the lemon juice and isopropyl alcohol?

While the leaked battery paste is potassium hydroxide, it is water soluble as are the corroded metal; if you think that simply washing it away is not good enough and you want to use kitchen ingredients, then why not use acetic acid (white vinegar)? Why exposé the circuits to lemon pulp and all the other junk from a squeezed lemon?  Secondly, the isopropyl alcohol is only 30% water (or 10% using the 90% isoPrOH solution); is this to dissolve grease?  Plain water will dissolve and wash away the corrosion, so the alcohol evaporates more quickly and this does what?  Clean away the "germs?" Yes it dehydrates and denatures the viral and bacterial cell walls, but do circuits care?

Please explain the chemistry, physics, and electronics behind this voodoo mixture

Vinegar smells like crap. Who wouldn't want a lemon-fresh Amiga?

[ferrellsl]

Both are acidic.  Why expose your delicate Amiga components that have already been damaged by battery acid to even more acid?  Baking soda and water is the appropriate solution.

[VuData]

Vinegar smells like crap. Who wouldn't want a lemon-fresh Amiga?

:biglaugh::biglaugh::biglaugh:

For some reason my A500 smells like a damp dog.

[danbeaver]

Both are acidic.  Why expose your delicate Amiga components that have already been damaged by battery acid to even more acid?  Baking soda and water is the appropriate solution.

I'm sorry you are thinking of a car battery based on hydrochloride acid; there are many ways to make a battery and the solid ones contain KOH ("LYE").

It makes no sense to use anything other than water to dissolve the metalic salts; but for those who need to use kitchen ingredients, acetic acid is at least more pure than lemon juice -- like anyone needs an Amiga to smell nice.

[kedawa]

I used butter on mine.
It's never run so smooth.

[danbeaver]

Don't forget the jam!  Breakfast Amy's are so soothing (add in a cup of tea with clotted cream)