A3640 in A3000D

[da9000]

I agree with joekster. Check your motherboard clock jumpers.

If I recall correctly, you want:

J104 = EXT
J102 = INT
J100 = EXT

I can check my machine later on to ascertain.

EDIT: the card should work fine with your custom chips (DMAC, Ramsey, Buster) and no matter if you have Static Column or Fast Page Mode ZIPs.

[da9000]

@jdryyz

OK, I hadn't looked at the posted link in detail (I only saw the A3640 jumper settings). Well, at least I got'em right! :-)

Unfortunately then it sounds like either an incompatibility or a dead A3640.

Here are a couple more things to try:

1) Put up the brightness of your CRT so that it's not black but grayish. Turn on the Ami and note if the color changes to an even lighter gray. If so, the CPU is good. Otherwise, replace the CPU and try again.

2) Assuming in the above test the CPU is good, put your nose very close to the SMD capacitors (5 of them IIRC), and smell them. If there is some nasty stench, they've leaked. Also check to see if their solder pads are fuzzy vs. shiny. If shiny, no leaks. If fuzzy, they've leaked.

3) Desolder and replace the crystal oscillator. It could be dead. Unusual, but it's a possibility. In fact, before you desolder the crystal oscillator, I'd personally get some el-cheapo electrolytic caps and replace the SMD ones. You'll need 22uF @ 16Volts. Here's more info you'll need, because they've been soldered on backwards:
http://amiga.serveftp.net/A3640_capacitor.html


Good luck!

[da9000]

alexh wrote:
Not true. There is a known problem with A3640 & A3000 with DMAC-02, RAMSEY-04 if you have Static Column ZIPs.

He said he has a A3640 (v3.1). As far as I know the problems with Static Column chips were with v3.0.

Where is the A3640 & DMAC-02/RAMSEY-04 documented?

[da9000]

jdryyz wrote:
it's hard to tell, really. They're just a little dirty looking but so are a lot of other spots on the board.

A picture (hi-res) is worth a thousand words :-)

jdryyz wrote:
That is interesting about the polarity of the caps. I do appear to have them all this way.

Not sure what you mean by "to have them all this way". What's "this" mean? Reversed or corrected?

jdryyz wrote:
If I was more daring and had the time and tools, I may have wanted to replace them but not now.

I thought you were in Canada, but I see you're in California. Not sure where Torrance falls, but if you're coming to AmiWest, then I can take a look and replace the caps for you (I posted about this someplace on the forum).

Good luck!

[da9000]

@T3000:

Sure! Check this post of mine for details:
http://www.amiga.org/forums/showthread.php?t=38302

[da9000]

@Alexh:

yes, you're right, I got my 3.1s corn-fused :-)

@jdryyz:

:-( Hope you can get one that's working!