Faulty Amiga 3000

AndyLandy

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So I've just gotten a hold of an A3000, but sadly the poor girl needs some attention.

When you power it up, the screen goes dark grey/medium grey/light grey perpetually. It looks almost as if it's just rebooting constantly. Any advice on what could be the cause, and what I can do to investigate?

The battery area looks to be fine, no signs of leakage there, but the case is very battered. I guess it's possible it's just an un-seated custom chip, but it could be something more-serious.

Any advice appreciated. :)
 

tokyoracer

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Try re-seating the ROM chip and if there are any Zorro cards, remove them.
If no luck, keep reseating the CPU card and clean the contacts, if still nothing then check the caps for leakage.

Best of luck mate, I wish I had an A3000, working or not. :(

P.s. If you have a spare CPU card, give that a go too.
 

AndyLandy

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Try re-seating the ROM chip and if there are any Zorro cards, remove them.
If no luck, keep reseating the CPU card and clean the contacts, if still nothing then check the caps for leakage.

Best of luck mate, I wish I had an A3000, working or not. :(

CPU card? Ha! I'm using the on-board '030. And no Zorro cards yet, they come later, when the machine /actually/ works. :)
 

Zetr0

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can't the A3000 boot kickstarts from disk?

is there a jumper for this...

I dont actually own an A3000.... yet....
 

AndyLandy

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can't the A3000 boot kickstarts from disk?

is there a jumper for this...

I dont actually own an A3000.... yet....

This is a later-model A3000, so I *think* it's got Kickstart 2.04 ROMs, rather than the crazy 1.4 MetaKick ROMs. That said, I can't say for sure.

It's a Rev 9.2 motherboard with 25MHz 68030/68882 on-board.
 

tokyoracer

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Try re-seating the ROM chip and if there are any Zorro cards, remove them.
If no luck, keep reseating the CPU card and clean the contacts, if still nothing then check the caps for leakage.

Best of luck mate, I wish I had an A3000, working or not. :(

CPU card? Ha! I'm using the on-board '030. And no Zorro cards yet, they come later, when the machine /actually/ works. :)
Oh yeah, it's onboard isn't it. . . Sorry. :roll:

Try the other suggestions though.
 

rkauer

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Move the tick jumper from external to video.

If no avail, chances are one of the TTL latches are fubbared. More on this problem later.

BTW: from what I know, the last motherboard version (yours is the 9.2, so it is the latest one) only came with the 2.04 ROM.

Reseat the daughter card, too.
 

Kin Hell

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^^^^^^

The Daughter card being the ZORRO riser. Also check for leaking caps, aka Sweaty looking tops or dull/furry contacts to the mobo. ;)

Be careful re-seating the Custom chips which are socketed. There is a lot of flex between the chassis mounts. Tbh, it's best done out of the chassis on a suitable anti-static suface.

Kin

PS. Is the Caps lock key doing any blinking routines? If not, what happens if you press the Caps lock key every second? - Does it stop responding? - ie, staying on or off.
 

AndyLandy

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^^^^^^

The Daughter card being the ZORRO riser. Also check for leaking caps, aka Sweaty looking tops or dull/furry contacts to the mobo. ;)

Be careful re-seating the Custom chips which are socketed. There is a lot of flex between the chassis mounts. Tbh, it's best done out of the chassis on a suitable anti-static suface.

Kin

PS. Is the Caps lock key doing any blinking routines? If not, what happens if you press the Caps lock key every second? - Does it stop responding? - ie, staying on or off.

Rattling the caps lock key eventually causes it to stick in the off position.
Hitting Ctrl+Amiga+Amiga resets this behaviour (So, clearly there's some semblance of Amiga behaviour under there) :)
 

Kin Hell

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Oh dear! :( A locking Caps Lock key means the CPU has stopped responding.

I dare say you will be needing some capacitors replacing m8.

Kin
 

Merlin

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Kin hell said:
Sweaty looking tops

That's bound to attract some comments......:whistle:

No wet T-shirt contests here, Kin; SdG won't allow them!!

:rofl3
 

rkauer

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On an A3000???? Those capacitors are "common" trough-holes capacitors that are not affected by the SMD-only capacitors plague.

But sure they can dry internally, reducing the capacitance to a point when they don't do their part in the circuit.

My bet is power-relating (where the big capacitors inside the PSU can misbehave the machine) or bad connection.

A last (but not irrelevant) problem is a fried chip due overheating (common on the PAL chips and some few "F" TTL around the board).

Also the "tick" circuit inside the A3000 PSU is prone to failure, so an innocuous probe is move the tick jumper (J350) to video source (position 1-2) to see if the circuit is acting correctly.
 

Kin Hell

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^^^^^^

Just awesome m8. :nod:

The Caps Lock key locking up is definitely a CPU failure to respond though. So what of your comments above, could be the culprit?

Swapping PSU's is a right old job.

Kin
 

rkauer

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Swapping the under-powered PSU (only 135W !!!) for a micro-ATX 400W replacement and moving the tick source to video make wonders for the A3000.

That's the first thing the A3000 owner need to do.
 

Kin Hell

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Swapping the under-powered PSU (only 135W !!!) for a micro-ATX 400W replacement and moving the tick source to video make wonders for the A3000.

That's the first thing the A3000 owner need to do.

@ rkauer

Can you post a link for AndyLandy to do this conversion? At least he's on the road to debugging this situation.

Kin
 

AndyLandy

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OK, changing the TICK source wasn't enough to rectify the problem. :(

I'm not sure I have the necessary skills to do a PSU mod. Not sure where else to go at the moment. :(
 
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