Amiga 3000 stuck in reset

[Prime]

I have two amiga 3000's that don't work.
I am trying to get atleast one running, by using whatever parts I need from the other.

Both have the exact same Symptoms:
Black Screen, dim green LED, caps lock fails after about 10 pushes.

Something is causing one of the Amiga's to be stuck in reset.

The other one is not stuck in reset, but same symptoms.

I got much help from this community a couple of years back, so hopefully we can revisit this!

Where to start?

Thanks!

[Prime]

A very tiny bit, maybe a small dot by the ground pin.

No damage or leakage to neighboring chips.

[Prime]

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

[Prime]

Nope, Amiga's will still work without a DF0 or floppy attached.

[Prime]

Yup, I tried that too.....

I am more curious as to what would be causing the CPU to be in reset.....
As long as it is in reset, nothing is going to work.

[Prime]

Ok, here is the latest:

I resocketed all the chips. I swapped some of the chips with some other ones I have and the cpu is not stuck in reset anymore however; it still has the same behavior.

Here is what I verified:
Clock lines on all chips are ok.
_fail is ok on GARY and on the RTC.
There is a present TICK signal, but I have also tried using VSYNC.

I put an O-Scope on different data lines on the cpu and see some bits going through the bus.

Now I am totally for a loss. All chips have clock signals and appear to be working correctly... ahhhhhh!

Help.

[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.

[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.

[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.