My A3000 is ill.

[Jtrim1]

Hey guys, I hope I can find some help to revive my seemingly dead amiga 3000.  Let me describe the problem briefly...

First off, I don't have a monitor that works with this 3000 (at least I don't think I do) but I'm using a standard SVGA monitor just in case it works.  I got this amiga from a repo sale, and it has never booted for me.

When I plug the power in, and I press the power button, The Power LED comes on for about a third of a second, then flashes on and off steadily and unendingly. I hear the hard drive make a weak buzz noise every 10 seconds or so, and usually the buzzes come in pairs.  like  buzz (2 seconds pause) buzz, then a 10 second or so wait and it does it again.

If I try to turn it on with a floppy in the drive,  I get no different reaction,  the floppy doesn't try to read or anything.  

Now, here's the really sucky part.  I've opened the case up and noticed the battery has leaked.  It doesn't look to have gotten up onto any components, and the leakage has pretty much stayed away from the Paula and Denise chips.  It looks like it headed toward the rear of the machine from the negative side of the battery.  It's mostly surface damage on the Circuit board, but the legs of several of the components have corrosion on them.   I have since cut the battery out of the motherboard, but haven't gotten a chance to clean it yet.  

So, there you have it, that's my current situation.  Anyone up to the task of helping me figure this one out?  I would appreciate any helpful suggestions.

Thank you very much!!!  P.S.  I can take some pics later on and post them if it would help anyone interested.

Jeremy Trim
Jtrim@woh.rr.com

[motorollin]

Does the power LED actually switch off, or does it just dim and brighten? If it switches off, then I would say there is a power problem. Either the PSU, or the power connector on the board, or the battery has eaten some of the board.

--
moto

[doctorq]

Remove the battery and clean the area where it has leakaged. Try booting the computer without anything extra connected (remove Zorro cards, etc).

The A3000 has a build in scandoubler, so connect your monitor to it and you should see some output on the monitor. You might need to use the switch at the back to get it to display 31 Hz video output.

[Jtrim1]

motorollin wrote:
Does the power LED actually switch off, or does it just dim and brighten? If it switches off, then I would say there is a power problem. Either the PSU, or the power connector on the board, or the battery has eaten some of the board.

--
moto

Ok, I cupped my hands around the Power LED so I could see more clearly what it's doing, and in fact, it's flashing, but it's going from bright green to dim green.  It doesn't actually flash on and off.  So, it's a steady bright/dim/bright/dim  probably 3 times a second is how fast it's flashing.

[motorollin]

Ok, so it's maintaining power, which is good. Dimming and brightening power LED suggests the machine is crashing and rebooting constantly. Follow doctorq's advice and try to get some video output from the machine. You will probably find you get a coloured screen which will indicate where the problem lies.

--
moto

[Homer]

Didn't someone previously mention a web page about diagnosing and fixing after similar battery problems ? Try a search through the old forum posts. Good luck :-)
P.S. Which part of the world are you in ?
P.P.S. Did you try unplugging everything including hard drives as mentioned before ??

[Jtrim1]

motorollin wrote:
Ok, so it's maintaining power, which is good. Dimming and brightening power LED suggests the machine is crashing and rebooting constantly. Follow doctorq's advice and try to get some video output from the machine. You will probably find you get a coloured screen which will indicate where the problem lies.

--
moto

alright, I've got the monitor hooked up to the 31khz 15 pin output on the back of the machine. Toggle switch is set to "Enable" and I am seeing something on the screen, but not much.   It's basically a black screen, and every .... holy crap... I just went over to check how often this little white line flashed randomly on the screen, and when I pushed the power button, I got a steady "on" power LED, which has NEVER happened before.   I'm still staring at a black screen however.  But, anyway, before it decided to give me a solid power LED, the screen was black, and a white line would flash up on the screen, in a random position, about ever 5 seconds or so.  Kinda like a quick signal on the screen, but not there long enough for the screen to synch and show me anything, so it just kinda flicked a white line.  

anyway, I have a solid LED bright green now, but I have taken out all periferals, so it's just the motherboard and a power supply.   Should I see anything on the screen?

[doctorq]

The daughterboard also needs to be installed.

[Jtrim1]

Homer wrote:
Didn't someone previously mention a web page about diagnosing and fixing after similar battery problems ? Try a search through the old forum posts. Good luck :-)
P.S. Which part of the world are you in ?
P.P.S. Did you try unplugging everything including hard drives as mentioned before ??

I've searched through the forums and found some good info on what to do after a battery has leaked, but I wasn't quite sure that this was the cause of my problems, so I wanted to post my symptoms and see what you guys thought.  

I'm in Dayton Ohio, and yeah, right now I'm running it with nothing but the motherboard and the power supply.  

And, by the way, I'm back to my flashing Power LED.  Looks like that Solid power LED was a one time deal, a small glimps of hope, maybe the amiga is trying to give me a sign of life so I won't give up on it.  

[Jtrim1]

doctorq wrote:
The daughterboard also needs to be installed.

Ok, sorry, I should have said that, the daughterboard is in fact still installed as well.  But no periferals are in any of the slots.  there was only one add-in card that came with the machine, it's some sort of video card, but I don't know what it is... It says "Opalvision" on the board.

thanks for your help!

[Homer]

Can you verify the psu outputs to the motherboard ? Do you have a voltmeter ?

[Jtrim1]

Homer wrote:
Can you verify the psu outputs to the motherboard ? Do you have a voltmeter ?

No, I haven't got anything to test the power supply, but the amiga seems to power on ok.  It just seems, as motorollin said, that the machine is crashing and rebooting constantly.  

Update on the video output.  It's sporadically giving me hints of a screen, it's very flickery, and if I had to describe the screen that is there, I'd say it's a solid gray screen.  But it's flickering rapidly, and it goes away for long periods of time.

[patrik]

@Jtrim1:

If the battery has leaked, the most probable cause of disfunction are damaged tracks on the pcb - the leaking fluid will corrode away the pcb.

Even if the chips are ok, if tracks on the pcb are broken, they need to be repaired (connected again).

Here is some info on this issue.

Atleast remove the battery and clean the area thoroughly as described in the above link now, as it is eating away the motherboard as you read this. If it is really bad, the stuff can have made way to the back side of the motherboard also, so check there too.


/Patrik

[Jtrim1]

patrik wrote:
@Jtrim1:

If the battery has leaked, the most probable cause of disfunction are damaged tracks on the pcb - the leaking fluid will corrode away the pcb.

Even if the chips are ok, if tracks on the pcb are broken, they need to be repaired (connected again).

Here is some info on this issue.

Atleast remove the battery and clean the area _thoroughly_ as described in the above link. If it is really bad, the stuff can have made way to the back side of the motherboard also, so check there too.


/Patrik

Thanks Patrik... I'm gonna get this thing home where I'll have more tools to work on it, and I plan to remove the motherboard, clean all the corrosion off and see what the traces look like.   I have pretty much no experience in electronics, so I don't know if I'll be able to really do much of anything, but I've got some friends or are electronics savvy, so perhaps I can get them to reconnect traces if at all possible.  Is this a very difficult thing to accomplish?  I've seen those conductive pens, would that be the sort of thing that would be used to reconnect a trace?

Thanks again for all your help!

Jeremy

[patrik]

Sounds like a good idea to give it a good clean and then just for the sake of it see if it works any better.

After that, one of your friends should be able to repair it quite easily if it is just damage to the top layer. It is a four-layer board (two layers in the middle, one on top and one bottom, so if it has eaten into the middle layers, it can become a real hassle.

It would probably be best to repair the tracks by connecting them again by soldering and thin wire.

Those pens tend to be rather bulky and the damage will most likely result in a very uneven surface, with possible penetration to the middle layers and if so, painting a new trace would result in a short-circuit, so I would advice against it. Anyhow, it depends on the amount of damage and the situation. Your friend should know, or else he should not be doing the repair .

Here you can find schematics for the A3000 if you need to do any trace-validation between pins on components when repairing.

Btw, pick the friend which is most skilled with the soldering iron.


/Patrik