A2000HD Battery Fun

[Darklight]

Well, as the name suggests, I guess you could say I've had a bit of a problem with a leaky battery in an A2000HD.  Check out this photo.
Evil Battery Remains

I bought an A2000HD and was given a complete second A2000, but disassembled, and with the mobo in that condition.  The battery was already gone when I received the board, and with a phone battery attached (that red wire was part of it) which had leaked again. :-o  It's a Rev 6 mobo, with ECS Denise and KS 2.04.  I've since cleaned it with isopropyl alcohol, and left it out overnight to dry.  I connected everything up to try it this morning, and it isn't booting.  All I get is a black screen.  Power LED comes on, Keyboard CAPS light comes on, screen stays black.  With an a2091 connected, the HD spins up.  I've cleaned all the corrosion from the legs of the 68000, but they still look pretty bad.  I've reseated the CPU, Kickstart, Denise, Paula and Gary several times.  I've tried to boot it without anything connected except a floppy drive and keyboard, still no go.  I also tried the 68000 out of the working motherboard (which also has a bit of battery damage, which I am going to clean up now   :-() and it still didn't work.  Any ideas of what I can do?  The screen is staying completely black, not black to grey or anything, but there is a change when the power is first turned on, which makes me believe it is functional at some level.
Anyway, any help would be great.  If I can't salvage it, I'll just raid the newer chips and put them on the older mobo I guess.
Thanks in advance.   :-)

[Castellen]

Most likely there will be a lot of corrosion on the 68000 socket contacts causing bad connection with the CPU.
The only way to fix it properly is to replace the socket.
Simple enough if you have reasonoble soldering skills.  The easiest way is to heat one leg at a time from the bottom of the board, and pull the pin up through the socket.
With removing the pins one at a time like that, there is less risk of damaging PCB tracks.

For the replacement socket, use one of the slightly more expensive machine pin contact ones if you can.  Not the cheap'n'nasty dual wipe contacts C= decided to use.

[adz]

@Darklight

I've got a whole array of spare chip and an early revision A500 board (to get clean sockets from) if your interested, I doubt shipping would cost all that much, PM me if you need anything.

BTW...see, us Melbournians are friendly ;-)

[Darklight]

@ adz

Thanks for that, I've sent you a PM.  Don't know whether I'll need it yet, but thanks for the offer.  

BTW, I know you Melbournians are friendly, it's the Queenslanders that don't like us Sydney-siders  :-D

[dEfEndEr]

And there was me thinking I was alone in this.

After spending 3 (oh, it's 4 now) hours trying to find out what was going wrong with mine, I took out the VXL*30 board to find what looked like a greeny had exploded everywhere.

So I'm in the same boat, off to maplins for a 68000 socket, some electronic cleaner, and a battery.

(death by battery acid)  :-(

P.S. I'm in the UK, and it's 4am here. I better get some sleep. or i'll miss my bids on eBay for the upgrade

[adz]

Darklight wrote:
@ adz

Thanks for that, I've sent you a PM.  Don't know whether I'll need it yet, but thanks for the offer.  

BTW, I know you Melbournians are friendly, it's the Queenslanders that don't like us Sydney-siders  :-D

And its the South Australians that don't like us ;-)

[Darklight]

LOL, I don't think the South Australians like anyone, except maybe the Tasmanians  :lol:

@ Castellen

Where am I likely to find a machine-pin 68000 socket?  Do you know of anywhere that sells them, or will I have to raid a computer to do it?  The other question is, I have a Mac Classic sitting here, does anyone know whether they use the same 68000 CPU, or one with a different form factor?

[adz]

You know I could desolder a socket from one of the spare motherboards I have here???

[BenShep]

When you were cleaning it you may have damaged some of the traces on the motherboard - this may prove difficult to fix.

[adz]

Another Melbournian :lol:

[z36ra]

I would seriously think about a replacement mobo. If you want to save it then fine,but you will need to check all copper tracings with a multimeter. Even this will not fix damaged IC's. After fixing one thing, you will find yourself trying to fix another and after all is said and done youve spent more than the damn thing is worth. You should consider wether your effort is being expended on an archialogical venture which is what I saw in your picture. A repair of this magnitude would take an expert sometime to pull off and the end result would still result in something akin to prescribing asperin for leukemia.

[Darklight]

Yeah, I figured it might be a hopeless venture, but I figured that I'd gotten it for free, so if I could get a working A2000 out of it, well then it would be worth it.  I can take another photo of it now if you want to see it, there's a bit of damage, but it looks for the most part, like I might be able to repair it.  I'll take a look at it with a microscope and see if any of the traces look broken.  I agree that it's probably beyond fixing, but seperate motherboards are hard to come by for Amigas over here in Oz, even for A2000's.  

@ adz

Which spare motherboards are you talking about?  A2000 ones, A500 ones, or Mac Classic ones?   :lol:
And :lol: another Melbournian.  I think I'm going to have resign to the fact that there's more Melbournians on here than Sydney-siders.  Ah well, the majority of Amiga stuff on eBay is up here  :lol:  :-P

[Castellen]

@ Darklight
For a replacement socket, you should be able to get one fairly easily from most professional electronic component retailers.
Start with Altronics/Dick Smith, but they probably won't have that size.
Farnell or Radio Spares probably will, but I think minimum order value is $20 or something.
You've got way more electronic shops in Aussie compared to us, so shop around. :-)

Don't use a 2nd hand socket.  For a start, you don't know the condition of the contacts inside.  Plus the best way to remove a socket soldered into a PCB is to completely wreck it.  To unsolder it you heat each leg one at a time from underneath and pull out the contact from the top.

To answer the question about corroded PCB tracks, it's possible some tracks have been corroded, but it's more likely that the 68000 socket is the main culprit.
The tracks in the A2000 are fairly thick and wide, so it takes a lot to damage them.
Problems usually occur in vias (the wee holes which make tracks join top and bottom PCB layers).  The battery chemical runs down inside the copper plated via hole and corrodes it.
I've illustrated it here:
http://amiga.serveftp.net/images/ViaRepair.jpg

It's a good idea to use a multimeter to check the continuity of tracks which have vias running near the battery area.
Can't quite remember, but I think the A2000 has the vias where the hole is filled with solder??
These are quite good, as the battery chemical can't run down inside.

[Azryl]

Toothpick soaked in metho, work it into all those CPU socket contacts, repeat and repeat, clean them out as best you can and maybe it will boot.. eventually

Yep.. worked for an a2000 I ressurrected with about that much battery damage, replaced with lithium battery hack and still working fine :-)

Better to do something like this before attacking the mobo with hot iron and solder ! lol

Az