The A2000 returned from the sea

[jman]

Sirs,

another old lady entered my home.

Finally I had time to grab the A2000 belonging to this friend of mine; he used to use first this before buying the A4000 I've restored (detailed here).

Unfortunately the situation for this A2000 is dire.

But first things first, here's a couple of screenshots for your voyeurism participation:
- Motherboard is a B2000-CR rev 4.4

- We have two expansion card:
1) A2090 SCSI controller (unknown version) with probably attached a MINISCRIBE-8425 HD capable of the gigantic size of 20mb.
2) SupraRAM 2000, unknown revision with 2mb

If interested, have a look for yourself to the rest:
http://www.storiepvtride.it/a2000/

The main issue here is that the computer has been kept for years in a garage near the seaside, those of you living near the sea will know very well that the salty air does not forgive.
The case is rusty in many places but worst of all I'm afraid there has been a massive battery leakage over the mobo:

and also somewhere else I see turquoise colored stuff :-(

This weekend I'll start extracting all components, clean, remove battery ... the usual stuff before attempting a power-on.

[8bitbubsy]

First use a set of pliers to cut off the battery pins, then bin it.
Second get a lemon (yes, you read right) and extract the lemon juice and pour it all over the battery leakage, on every spot that has this tint turquoise color. The lemon juice will start to attack the alkaline "acid" so that it gets mostly removed and prevented to grow any further. Let the lemon juice lay on top of the alkaline for some minutes, more and longer is better.
After you're done, take it to the shower and do a hot cleaning session (no soap, only hot water) to remove the lemon juice, loosened alkaline and all the dust.

Don't use lemon juice on bottles made for food or so, as they contain other chemicals you don't want, I think.

[rkauer]

Lemon juice is also good to remove the rust from the iron case.

[jman]

Originally Posted by 8bitbubsy

After you're done, take it to the shower and do a hot cleaning session (no soap, only hot water) to remove the lemon juice, loosened alkaline and all the dust.

Do you really mean putting it under a hot water stream?
I've always been puzzled at suggestions like this (also those about putting the motherboard into the dishwasher).

Giving for granted that the circuitry must be properly dried out after washing, but is it true that nothing gets damaged? Metal is ok, but I'm thinking to small plastic things here and there, small glue dots...

thanks

[prowler]

Originally Posted by jman

Do you really mean putting it under a hot water stream?

Yes, it's really not going to harm your Amiga.

Originally Posted by jman

Giving for granted that the circuitry must be properly dried out after washing, but is it true that nothing gets damaged? Metal is ok, but I'm thinking to small plastic things here and there, small glue dots...

We're not talking about steam-cleaning here. Hot water from a shower head can never get hotter than 100ºC, which is a lot less than the melting point of solder, so there will be no danger from the heat, and any glue used will certainly not be water soluble (though it may temporarily soften slightly while the board is warm).

Plus, there will be no danger from electrostatic discharge while the board is wet, with the water being an excellent conductor and all.

Go for it!

[jman]

Originally Posted by prowler

Yes, it's really not going to harm your Amiga.

Thank you for your info, I did wash that motherboard and shot it with a hair-drier. Tomorrow I will keep it to the warm sun of the morning to be sure it is dry.

Before washing it I poured lemon juice over the battery and the nearby circuits for a while but I didn't see the usual crystal "frying". Unfortunately the battery was empty and the acid has gone completely all over the motherboard and had all the time needed to spread, eat the circuits and dry. I can clearly see a big stain all around (picture before cleaning):
www.storiepvtride.it/a2000/leak.jpg

Some parts appears to be clearly oxidized even after washing. I'm worried about all these damages:
http://www.storiepvtride.it/a2000/damage.png

What do you think I can do? I can patiently remove the green oxide with a brush, but what for? And what about those soldering points?

[prowler]

Originally Posted by jman

Thank you for your info, I did wash that motherboard and shot it with a hair-drier. Tomorrow I will keep it to the warm sun of the morning to be sure it is dry.

That should do it, but make sure you're absolutely certain that all the water has evaporated before you power it up.

Originally Posted by jman

Before washing it I poured lemon juice over the battery and the nearby circuits for a while but I didn't see the usual crystal "frying". Unfortunately the battery was empty and the acid has gone completely all over the motherboard and had all the time needed to spread, eat the circuits and dry. I can clearly see a big stain all around (picture before cleaning):
www.storiepvtride.it/a2000/leak.jpg

Actually, it doesn't look as bad to me as others I have seen which have eventually been restored.

Originally Posted by jman

Some parts appears to be clearly oxidized even after washing. I'm worried about all these damages:
http://www.storiepvtride.it/a2000/damage.png

I would have applied the lemon juice to the exposed parts of the board with a stiff brush made by trimming the bristles of a 12mm paint brush to about 10mm length. This might have removed some of the oxide.

Originally Posted by jman

What do you think I can do? I can patiently remove the green oxide with a brush, but what for? And what about those soldering points?

As I have said, it doesn't look that badly damaged to me, so I would wait for it to dry thoroughly, and then power it up to see if it shows any sign of life.

If it works, then I would try to remove as much of the oxide as you can with a dry, stiff brush like the one I described above, but no solvent. You may have to lift the chips out to clean their pins and sockets properly.

Then, when it's as clean as you can get it, retest it and if all is okay I would prevent further oxidation by applying a clear lacquer (nail varnish will do) to as many of the exposed tracks as you can.

Let us know what happens when you power it up for the first time.

[jman]

Originally Posted by prowler

If it works, then I would try to remove as much of the oxide as you can with a dry, stiff brush like the one I described above, but no solvent. You may have to lift the chips out to clean their pins and sockets properly.

I tried to scratch the oxide from a zorro slot and I see that how easily goes away easily, but then unfortunately I did a big big mistake.

I removed the 68000 the check under it and I scratched the chip pin slots too and next thing you know I did broke three pin slots of the CPU!!!! :-((

The damn zorro pin slots are so flexible, the 68000 ones are sooo easily broken!!! Goddammit, someone could have warned me those damn pin slots, they are not flexible, they are fragile like a dried leaf...

Now what the f++k am I supposed to?!?!?!?! Do I have to flood it with soldering tin in order to be sure that the cpu pins make contact???? what the hell, better stop it now before throwing everything out of the window, I'm furious!! f++k my life

[lost_loven]

maybe you can solder a wire from the cpu to where it leads to on the mother board?

lost

[Wolfy]

Not the end of the world, 64pin dil socket:
http://www.ebay.co.uk/itm/1-PC-64-PI...item335bc2e559

Lifes good mate, you are rescuing a miggy 2000!

[8bitbubsy]

Originally Posted by Wolfy

Not the end of the world, 64pin dil socket:
http://www.ebay.co.uk/itm/1-PC-64-PI...item335bc2e559

Lifes good mate, you are rescuing a miggy 2000!

Are you sure this one fits? Remember, the Amiga 68000 CPU socket is fatter than the other sockets.

[jman]

Originally Posted by lost_loven

maybe you can solder a wire from the cpu to where it leads to on the mother board?

I think the best solution is connecting the CPU like you suggest, it reminds me of some PlayStation 2 modding video on youtube :-) it must not be that hard.
Problem is that I'm not very skilled with the solder tool, that's why I sort of lost my temper, sorry. Well, my bad, time to learn this too.

@Wolfy
Probably there's no need for such a deep replacement, after all only 4 pins are gone. But thanks for the input, it may come in handy another time, now I know the name of that component.

On a side note, I've found an easy+cheap way to clean oxidized metal: use the usual product you have in your house for cleaning the water closet and the bathtub. The metal won't go back to its original state but the surface will get very smooth and all the dirt will be removed.

Warning: DO NOT USE SUCH PRODUCTS ON ALUMINIUM!

[rkauer]

SIL sockets are the best for the task.

Cut they in the correct length (two 32 pins rows) and replace the broken socket with it.

About the board itself: do a buzz (continuity) test on the darkened traces, as they may get interrupted by corrosion. Normally the battery leakage goes under the CPU socket, so it's wise to replace it anyway.

[JHawk]

Originally Posted by 8bitbubsy

Are you sure this one fits? Remember, the Amiga 68000 CPU socket is fatter than the other sockets.

The measurements seem correct - 22.86 mm is .9 inch. I bought a .9 inch socket from Maplin in the UK for one of my Amigas.

Good luck with the restoration!

[jman]

Originally Posted by rkauer

About the board itself: do a buzz (continuity) test on the darkened traces, as they may get interrupted by corrosion. Normally the battery leakage goes under the CPU socket, so it's wise to replace it anyway.

While I'm waiting to receive the wire wrap for the CPU "modding", I'd like to do such a test.

But I must ask if you can kindly elaborate a bit on this. I'm not very familiar with this procedure, I need a little hand-by-hand help about this. Do I need to use the multimeter, correct? Where do I need to put positive and negative poles? Which voltage shall I check for?

Only if I find problems I'm willing to replace the CPU socket, for I'm not very skilled on soldering, that's the last resort :-)

Thank you very much for your help.

[8bitbubsy]

Put the multimeter in diode mode (beep mode). It doesn't matter what probe you put where, it's just to check if a trace is not cut/broken. Think of it as a way to check if the power runs from one probe to another.

[jman]

Originally Posted by 8bitbubsy

Think of it as a way to check if the power runs from one probe to another.

Ok after a couple of youtube tutorials I've understood what you're talking about :-)
My multimeter doesn't beep because I felt cheap the day I've bought it :-) however I have readings everywhere like the one attached.
In that picture the triangle in red is the battery placement, that's the place of the motherboard in worst conditions.

Does the figures indicated on the multimeter are meaningful or any value is a good value? I'm asking because for example crossing the sticks returns immensely higher values.

Thank you guys, you are so kind with the mentally challenged LOL

[altcomputing]

In short, only a 0000 or 0001 reading means 100% contact; but i wouldn't care much about the battery; even if it didn't work, you'd only be unable to keep the clock running when amiga power is shut down... not a big issue, really.

Anywhere you find a clear trace point to point but no contact, just run a wire. It will live!

[Paul_s]

The thread title says the A2000 you had came from the sea.

Where do you fish and can you try and find me an A3000T please? I guess you'll need a crane for that.

[jman]

Originally Posted by altcomputing

In short, only a 0000 or 0001 reading means 100% contact; but i wouldn't care much about the battery; even if it didn't work, you'd only be unable to keep the clock running when amiga power is shut down... not a big issue, really.

absolutely. I don't care about the battery, I just tested that area because it was ground zero where it leaked.

To summarize, I didn't spend a whole evening testing but to a rough check "here and there" there appears to be no dead ends. Let's see what happens when the current will flow again through its veins...

@Paul_s: Poseidon told me that currently he didn't have a A3000 in stock, will stop by his shop in a couple of weeks to see if he has anything else, I need some hardware too ;-)

EDIT: Paul_s, have a look at here, lots of stuff, but - God - prices are scary ...