is my A4000 dead?

[dirkies]

For the first time in about 10 years I fired up my A4000 desktop rev D (was always stored in a dry an ambient room) but unsurprisingly it did not get far. It does power up, HDD spins up, DVD, leds come on etc.
But the PIV outputs just a black screen (so LCD monitor gets a signal) and the power led cycles 1 bright time and then 6 blinks in an endless loop.

So I decided to take the whole thing apart (it is pretty pimped up!) and see what can be noticed.

Some things not looking right:

Power supply caps (the black ones), or is that glue?!:
https://plus.google.com/u/0/photos/1...44341231334552

Capacitor C200:
https://plus.google.com/u/0/photos/1...44341231334552

Capacitors C404 and/or C443 and the resulting (?) "green" legs of U402:
https://plus.google.com/u/0/photos/1...44341231334552

another shot of same situation:
https://plus.google.com/u/0/photos/1...44341231334552

All the rest looks OK. Underside of PCB also looks pristine everywhere.

So could this capacitor crap be lethal to the board? The machine normally has a Cyberstorm MK2 060 with SCSI2,146MB RAM + PicassoIV, Toccata, Maestro, USB and Ethernet card, and 2xHDD floppies, SCSI DVD and HDD.

As I said, it has been a while, but last time it worked fine using OS 3.9 networked etc. Battery was already removed before the A4000 was stored 10 years ago, so no leakage whatsoever ever occured.

And my next question will then be, where can I repair this if it can be? Amigakit (recap)? Or does it require more advanced repair? What is U402 and does it need replacing?

I will not reassemble it all just to see if it now works, as I think these capacitors were naughty over the past few years.

[Jope]

It's a very good idea to replace them, but don't be disappointed if it doesn't fix your problem.

[jbenam]

Changing the caps won't hurt, but the problem might not lie there.

Testing the bare A4000 motherboard without all that stuff hooked to it will sure help in diagnosing the problem though

Try that and let's see what happens.

[dlfrsilver]

Originally Posted by dirkies

For the first time in about 10 years I fired up my A4000 desktop rev D (was always stored in a dry an ambient room) but unsurprisingly it did not get far. It does power up, HDD spins up, DVD, leds come on etc.
But the PIV outputs just a black screen (so LCD monitor gets a signal) and the power led cycles 1 bright time and then 6 blinks in an endless loop.

So I decided to take the whole thing apart (it is pretty pimped up!) and see what can be noticed.

Some things not looking right:

Power supply caps (the black ones), or is that glue?!:
https://plus.google.com/u/0/photos/1...44341231334552

Capacitor C200:
https://plus.google.com/u/0/photos/1...44341231334552

Capacitors C404 and/or C443 and the resulting (?) "green" legs of U402:
https://plus.google.com/u/0/photos/1...44341231334552

another shot of same situation:
https://plus.google.com/u/0/photos/1...44341231334552

All the rest looks OK. Underside of PCB also looks pristine everywhere.

So could this capacitor crap be lethal to the board? The machine normally has a Cyberstorm MK2 060 with SCSI2,146MB RAM + PicassoIV, Toccata, Maestro, USB and Ethernet card, and 2xHDD floppies, SCSI DVD and HDD.

As I said, it has been a while, but last time it worked fine using OS 3.9 networked etc. Battery was already removed before the A4000 was stored 10 years ago, so no leakage whatsoever ever occured.

And my next question will then be, where can I repair this if it can be? Amigakit (recap)? Or does it require more advanced repair? What is U402 and does it need replacing?

I will not reassemble it all just to see if it now works, as I think these capacitors were naughty over the past few years.

I see leakage everywhere there are capacitors. Those have leaked (check the latest picture, you have something like an SMD 74LSXXX with its legs blue.

I guess that out of the cleaning of the damages done by the capacitors, there will be some chips like those 74LSXXX to replace by new ones.

[voyager]

Remove al the cards, only the bare minimum (motherboard + daughterboard and 2mb ram in the first slot. Connect scart and see what is does then, what do the error colors tell.

[jbenam]

Originally Posted by voyager

Remove al the cards, only the bare minimum (motherboard + daughterboard and 2mb ram in the first slot. Connect scart and see what is does then, what do the error colors tell.

I'd remove the daughterboard too, it just oscillates too dangerously when it's not in the case. You could damage the pins that way

The A4000 doesn't need it to boot, by the way.

Being a Rev D. this one has got the 2MB Chip already soldered on board. So he can just remove all the RAM sticks altogether.

If it's a Rev D that means it also has got a 030 soldered on board - it's worth removing the CPU card and trying booting with that one (might need to switch some jumpers on the motherboard to 030 if you're using a 040 now).

Also keep in mind that when booting without floppy drives attached it'll take longer than usual for the Kickstart screen to appear - so don't despair yet if you don't see the usual screen appearing after the normal amount of time

[jack-3d]

Same happened to me last week. I bought A4000T, first start Green led blink 6 times and recycle reboot.

I dismounted all components, cleaned all connectors, removed old battery, removed dust from everywhere especially PSU and started Amiga only with accelerator and floppy. It booted well, so then I continued component by component (added HDD, then GFX board, NIC, ...). Amiga works fine now.

[ancalimon]

Amiga needs a a stripping once in a while.

[dirkies]

I am reluctant to do the reassembly part as the capacitors are dying anyway, could risk sooner or later other components when the capacitor is dead completely.
And as it was originally a 4000/040 it has no onboard CPU, but visual inspection shows the 060 card in pristine condition.
I guess I will have it recapped by Amigakit first, maybe they also offer some "healthcheck" service to see for other things that they could fix for an extra?

[dirkies]

Or are there other people on this board who did a complete healthcheck with someone from here? Wasn't there a company in France doing that, incl repairs etc?

[jbenam]

Originally Posted by dirkies

I am reluctant to do the reassembly part as the capacitors are dying anyway, could risk sooner or later other components when the capacitor is dead completely.
And as it was originally a 4000/040 it has no onboard CPU, but visual inspection shows the 060 card in pristine condition.
I guess I will have it recapped by Amigakit first, maybe they also offer some "healthcheck" service to see for other things that they could fix for an extra?

Dead capacitors won't damage much - they will just do funny stuff and things won't work properly.

I suspect there might be a super-rare case in which something damage COULD happen, but I never heard of it.

The 060 might be in pristine condition, but sometimes you need to clean the connectors for everything to start working again

If you don't want that's up to you - but cleaning out all the connectors is usually the quickest and cheapest (free!) option to try getting your Amiga working again.

Originally Posted by dirkies

Or are there other people on this board who did a complete healthcheck with someone from here? Wasn't there a company in France doing that, incl repairs etc?

I don't know if things have changed from 6 months ago, but I remember reading around tha he didn't send back some stuff and stopped answering to emails.

I hope he did get everything sorted out and that everything was just a big mistake - but it'd be better for you to look around for comments and such about a technical center / repairer before sending out stuff.

[dlfrsilver]

Leaking from capacitors corrode the tracks on the motherboard. Dirkies motherboard has goo everywhere there are caps ! This has to be cleaned with citrus (it kills acidness), and the chip with blue/green crap must be replaced.

[multivac]

There are a few people repairing A4000s in the UK and one in New Zealand. I'm not sure if they post on this forum so I won't mention them but PM me and I'll send a list.

[demolition]

Originally Posted by dlfrsilver

This has to be cleaned with citrus (it kills acidness), and the chip with blue/green crap must be replaced.

You cannot kill acid with more acid (citrus=acidic). Citrus is good for battery leaks, not capacitor leaks. Batteries contain alkali which is basic (opposite of acidic).

Detergent is a mild base, so it can be used to clean up capacitor electrolyte leaks.

When a board goes bad due to capacitor leaks, it is usually not the capacitors themselves which causes the Amiga to not boot, it is more likely the corrosion which have broken one or more traces/vias. The fix here is to first remove all the aluminium electrolyte caps, clean up the mess and then start tracing the relevant areas (might be easier before the new caps are soldered in).