Amiga 3000 stuck in reset

[stevenlcroucher]

Both of my A3000s had this problem and in my case swapping the Dmac chip for a new one sort of fixed it, but it didn't last long as the machine stopped seeing its fast ram after a while.  I suspected another component feeding the Dmac had a fault.  I never did get to the bottom of it.

[Prime]

Yes, both boards were working when I had them.

One of them was very flaky and just died one day.

The other one (The one I am leaning toward fixing because the board itself is in very nice condition) died when I was near the battery area. I de-soldered the battery, and put in 3.1 roms and it croaked. (I did put back in the working 2.04 roms)

Buster - 390539-07
Ramsey - 390541-04
Gary - 390540-02
DMAC - 390537-02
Agnus - 318069-03
Paula - 252127-02
Denise - 390433-02

I have all fast ram banks empty.

Since then, I have cleaned the battery area very well.

I am guessing it would be in that area since that is the only area that has been touched.

I will probably just re-flow some of the solder joints in the area to see if that helps.

The two most suspect chips are the U477 & U480.

I socketed them both, however I may remove them and look at the traces around that area.

[nicholas]

I have everything stripped out of it but the daughter card. (So I can probe the chips)
Just the bottom chassis and PSU remain.

My A3000 won't start up unless the daughter card and DF0: are both connected.

[TheGoose]

My A3000 won't start up unless the daughter card and DF0: are both connected.

Hmmm. That makes sense to me...

[Prime]

My A3000 won't start up unless the daughter card and DF0: are both connected.

I think the problem I have is much lower level than "Starting up"

To me, starting up means either booting or showing the Insert workbench screen.

My system isn't even getting to a test phase.

The LED on the front should turn light green then brighter green right away.
That should happen I am guessing even if the daughter card is not connected, or a floppy (DF0).

Now of course, the system will give you some color screens and complain afterward, but mine doesn't even get to that point.

I would be extremely happy just to see color errors on the screens, at least that gives you some information!

Mine is dying right out the gate.

[TheGoose]

I think the problem I have is much lower level than "Starting up"

To me, starting up means either booting or showing the Insert workbench screen.

My system isn't even getting to a test phase.

The LED on the front should turn light green then brighter green right away.
That should happen I am guessing even if the daughter card is not connected, or a floppy (DF0).

Now of course, the system will give you some color screens and complain afterward, but mine doesn't even get to that point.

I would be extremely happy just to see color errors on the screens, at least that gives you some information!

Mine is dying right out the gate.

Well, humor us and connected them. Otherwise, I'd agree that it does sound like there is a short, (basically what a reset is). Maybe enough corrosion has jumped a gap some where.

[Prime]

I am at the point right now where I will turn it on standing on my head if I thought it would work, so I will try anything!

I tried it with the Daughter board by itself, it still fails.

I will have to wait till I get home from work to try the floppy and the daughter board together.


Thanks!

[Prime]

I just remembered that I had an Amiga 3000 floppy drive in my car!

I fired it up with the floppy attached and the daughter board attached and nothing.

I am loosing hope once again for this poor 3000.

[TheGoose]

I just remembered that I had an Amiga 3000 floppy drive in my car!

I fired it up with the floppy attached and the daughter board attached and nothing.

I am loosing hope once again for this poor 3000.

Shoot. Strange they both act this way. I'm out of easy tests...
Um, except checking the PSU with a multi-meter.