A3000 Repair Advice Desperately Needed

[kamek]

Howdy, I'm a relatively new person to the world of Amiga Computers, this is my third time stating this as I've been collecting advice from R/Amiga and AmigaLove but this site was also suggested, so I'll summarize:

Bought an Amiga 3000 for next to nothing, used by an og user until 2001 and then likely sat in storage for 19 years. It came with original manuals, a security key, some added cards, and a Commodore 1084-s-d monitor.
It has 2 Quantum HDDs in it, and a Floppy Drive I mistakenly took to be damaged initially. (Pictures here)


On bootup it would only display half the screen, I quickly switched to a VGA monitor, and took the spare cards out, as well as removed the battery.

Another user on Reddit suggested booting into AmigaDOS and renaming the CD0 to "rid of the error message from CacheCDFS", error message caused by it trying to get to a non-existent CD Drive. There was no CD0 present, instead a file called EMERGENCYCD.info, which I promptly renamed, slightly impoving the half display but not by much. (Picture) ( [ Show youtube player ])

I'm in the process of making a video dissembling the thing for further advice.

I have already ordered a spare floppy drive from an A2000 and some Workbench 3.1 Disks, as a user on AmigaLove suggested.

I am also not against sending it somewhere for repair, although I would prefer to keep it within my country. If you have a place please suggest it I am still doing research into that (I'm from the United States/DC Metropolitan area).

I would also like to say I appreciate all the support I have gotten from the Amiga community. Thank you.

[dalek]

Close up photos of the battery area and surrounding chips?

Likely you got battery acid damage around Denise / other parts of the video circuit.

[kamek]

Originally Posted by dalek

Close up photos of the battery area and surrounding chips?

Likely you got battery acid damage around Denise / other parts of the video circuit.

Cleaned it thoroughly, doesn't seem like it is but then again I'm new so might be something you see that I don't.

Pictures: https://imgur.com/a/kq98Lqv

I also made a video here, looking in (do wait for Youtube to give it a good quality though): [ Show youtube player ]

[amiman99]

Try to boot the Amiga with out the startup-sequence. To do that, hold both mouse buttons and power the system.
Then select boot without startup-sequence.
Then in CLI window type loadwb, and you should see the desktop. You may get some ENV errors, just dismiss them.
This will load clean Workbench with no drivers.

[pipper]

How does the image look like when connecting the monitor/tv via the rgb connector, not vga?

On the first video one can see a slot metal piece wedged in between the vidiot hybrid and the vga connector... did you remove that for the tests?

[dalek]

I'd pop out the Denise chip and inspect the socket and do a continuity test around there. Diagrom can be used to check if you have some dodgy chipram which can also give video issues, but since your systems boots you could also use Keir Fraser's Amiga Test Kit: https://github.com/keirf/Amiga-Stuff/releases

FYI, wrapping boards in fabric and running your system on carpet is a sure fire way to fry chips with static, leading to intermittent then complete failure. Just google ESD chip failure if you are a doubter.

For troubleshooting, a great help to me was loading Chucky's ReAmiga 3000 sprint layout files into the demo version or sprint 6 and using the 'x' key to follow traces: http://www.reamiga.info/?page_id=40

Edit: from your pic you can see at least some acid in the Denise socket

[kamek]

Originally Posted by dalek

I'd pop out the Denise chip and inspect the socket and do a continuity test around there.
Attachment 66144

Alright I'll get on that, would something like this suffice?
Also what would be the easiest way to take out the chip? I know they sell tools for that sort of thing.

Originally Posted by dalek

FYI, wrapping boards in fabric and running your system on carpet is a sure fire way to fry chips with static, leading to intermittent then complete failure. Just google ESD chip failure if you are a doubter.
Attachment 66144

I don't doubt anything... thank you for informing me, I have no experience with any of this, so good to know information! I really need to be directed so don't be afraid to withhold any kind of information!

[kamek]

Originally Posted by pipper

How does the image look like when connecting the monitor/tv via the rgb connector, not vga?

On the first video one can see a slot metal piece wedged in between the vidiot hybrid and the vga connector... did you remove that for the tests?

I did.

It's not much better; the unit came with a A520 Modulator honestly the image looks much worse, so washed out and a lot of ghosting. I'm grateful for the user over on r/Amiga who explained how the scan-doubler works.

[ajk]

Originally Posted by kamek

Also what would be the easiest way to take out the chip? I know they sell tools for that sort of thing.

The first DIP extractor tool you will find is probably something like this:



However I would advise AGAINST using these with a Denise or other large chip. They don't open wide enough and chips with 48 pins require a lot of force to extract, so most likely the tool will slip. Even if the chip does come out it will probably happen suddenly, in an uncontrolled fashion and pins may be bent.

What I have found to work best is a simple lever of some sort. The flat screwdriver on a swiss army knife like this works great:



This is better than most regular screwdrivers since all the edges are smooth, so you won't easily scratch the chip or socket. Remove the chip by inserting the tool between the chip and socket at one end, lever a bit, switch to the other end and repeat. You want the chip to come straight up, not peel it off the socket at an angle.

There are also bespoke DIP extractor tools for this purpose, however I don't know if any are large enough to handle the 48 pin chips (most I've seen can only handle up to 40 pins).

[dalek]

Originally Posted by kamek

Alright I'll get on that, would something like this suffice?

for diagrom yes - but it's free at diagrom.com if you are able to burn your own eproms.

Originally Posted by kamek

Also what would be the easiest way to take out the chip? I know they sell tools for that sort of thing.

flat bladed screwdriver - remove the daughterboard first. gently prise between the chip and the plastic socket (not the pcb) to raise each end about 2mm at a time. Be careful to only pull straight up gently after raising each end to not bend pins. If you have some contact cleaner you can spray that in the socket first to help deoxidise and lubricate the pins first.

After the chip is out you'll want to neutalise the battery alkaline on the socket contacts with some vinegar, clean with IPA and then ideally spray some contact cleaner in before reinserting the chip. The pins on the chip may need the same treatment too.

Originally Posted by kamek

I don't doubt anything... thank you for informing me, I have no experience with any of this, so good to know information! I really need to be directed so don't be afraid to withhold any kind of information!

Cool - some people are non-believers!

I'd suggest watching a few youtube vids from different people on amiga repairs - you'll quickly work out what's good and what's not - try GadgetUK164 to start with - he's done a lot of battery cleanup recently.

[kamek]

Originally Posted by ajk

What I have found to work best is a simple lever of some sort. The flat screwdriver on a swiss army knife like this works great

Fantastic I can get on that soon, check it and then you should just able to pop it back, assuming its fine?

Originally Posted by dalek

Cool - some people are non-believers!

Jeez. Going for help on forums where people have devoted themselves to a computer that stop being produced 30 years ago.... and not believing their advise? Thats some mental gymnastics.

I have been watching lots of Youtubers! but thank you I'll add that to my list.

[ajk]

Originally Posted by kamek

Fantastic I can get on that soon, check it and then you should just able to pop it back, assuming its fine?

Yeah, and perhaps clean the pins and socket with something like DeoxIT while you are at it.

[kamek]

Originally Posted by ajk

Yeah, and perhaps clean the pins and socket with something like DeoxIT while you are at it.

I went ahead and did that, the immediate results were great! Turned on to the Disk Screen, but after the screen graphics glitched out and then it went black and now powering it turns it to a black screen.

and yeah the Corrosion under the Chip is more obvious.

https://imgur.com/a/maKwdeW

[ajk]

Yeah, that corrosion definitely needs to be addressed. A good cleaning could be all it needs, but it might turn out that the socket needs to be replaced. If you aren't comfortable doing that sort of soldering work, I'd suggest contacting someone who does have the experience, in order not to cause additional damage.