Dead 2000

[curtis]

Finally got my 2000 back on the workbench and now it won't boot.

My symptoms are a black screen and 10 short blinks and 1 long blink on the power LED.

I've swapped out both the cpu and the ROM for known goods and no joy.

Checked voltages on the power supply and they're good.

I've got an Indivision installed and I don't even get the "splash" screen from it.

Suggestions?

Oh, it's a rev 6.2 motherboard.

Right now there are no boards installed at all.  It's basically bare metal with only a floppy drive.

[amiman99]

http://www.amiga.org/forums/showthread.php?t=20817
Check post #7

[JuMa]

Try pushing/reseating all socketed chips especially Agnus. Might also be bad contact at cpu socket. Try cleaning it with contact cleaner.

[scuzzb494]

Finally got my 2000 back on the workbench and now it won't boot.

My symptoms are a black screen and 10 short blinks and 1 long blink on the power LED.

I've swapped out both the cpu and the ROM for known goods and no joy.

Checked voltages on the power supply and they're good.

I've got an Indivision installed and I don't even get the "splash" screen from it.

Suggestions?

Oh, it's a rev 6.2 motherboard.

Right now there are no boards installed at all.  It's basically bare metal with only a floppy drive.

I have one of my A1500s that performs exactly the same. I have to switch off from the back and switch back on again. A softboot wont work. I just have to fire up again. Are you sure the video connector is working and is seated properly. Never used an Indivision. I found that the problems with the 2000 are mostly related to cards not seated properly or the main CPU. It needs a good connection so clean and check. That would generally throw up a colour but you never know. Dust off the board with the case out and just reseat but be very careful.

I've had a tricky time with 2000s this year and I've had a variation on your issue. All though were resolved with just minor issues to connectors. I switch on four of them every day just to check and they all work. Like I say that one 1500 sometimes needs a reset from the power switch to get her working. More annoying than a real problem.

Good luck.

[curtis]

@amiman99  Guess I'll have to find some DRAM chips and give it a whirl.

@JuMa  Tried that several times.  No joy.

@scuzzb494  Repeated power cycling doesn't do anything.  Double checked the INdivision and no joy there.  Firmly seated.

Looks like amiman99 has the right idea.  Now to order the chips!

Sigh...

[orange]

has the battery leaked?

[curtis]

has the battery leaked?

Battery is long gone.

[BLTCON0]

@amiman99  Guess I'll have to find some DRAM chips and give it a whirl.

@JuMa  Tried that several times.  No joy.

@scuzzb494  Repeated power cycling doesn't do anything.  Double checked the INdivision and no joy there.  Firmly seated.

Looks like amiman99 has the right idea.  Now to order the chips!

Sigh...

I wouldn't put my money on chip RAM problems (the system should be alive enough in that case to produce a green screen instead of a black one) but a quick test without any extra chips is:
desolder RP502 and replace with equivalent individual resistors, such that Agnus RAS0 gets routed to U505-U508 and RAS1 gets routed nowhere (i.e. the U501-U504 bank, where a chip problem would most likely be anyway, is cut off). See the schematics for further clarification.

That way, you relocate the base chip RAM to the (most likely) good U505-U508 RAM bank. If it works, you know there's a bad chip somewhere in U501-U504.

[curtis]

Don't where you got green screen.

My startup screen is BLACK.  Just like nothing is firing.  Not even the Indivision splash screen.

And replacement RAM chips are on the way.

[Oldsmobile_Mike]

Any difference from the composite video out?

[BLTCON0]

Don't where you got green screen.

From the standard error-colours the Amiga uses - when something's wrong with chip RAM in general (RAM chips, Agnus or possibly other custom chip, data path to chip RAM) it presents a green screen, not a black one.

Thankfully ROM is not behind the chip RAM buffers, so a problem in the chip RAM subsystem does not affect ROM code execution. Therefore if the problem is chip RAM restricted, the ROM code will still execute, detect the problem and switch to green error colour. It wouldn't normally stay black.

My startup screen is BLACK.  Just like nothing is firing.  Not even the Indivision splash screen.

Yes, you were perfectly clear about that. Which is why I suspect it's not the RAM chips (see reasoning in previous post and further explanation in this one).
The Indivision doesn't display its splash screen from chip RAM anyway, but from its internal buffer, so its absence is not an indicator of chip RAM fault.

And replacement RAM chips are on the way.

Let's hope then I'm wrong and the new chips will sort the problem out :-)

[curtis]

Guess this thread will go dormant for a couple of weeks while waiting for the chips to come from China!

Stand by to stand by...

[magnetic]

Guess this thread will go dormant for a couple of weeks while waiting for the chips to come from China!

Stand by to stand by...

Hey Curtis sorry for your problems. I always hate when something is wrong with my amigas! Is that the board I sold you? I was happy to see you having a nicely built a2k from it.

[mechy]

Guess this thread will go dormant for a couple of weeks while waiting for the chips to come from China!

Stand by to stand by...

wish you had asked curtis, i have loads of 256x4 dip ram chips(i think rev 6 uses those?)

[magnetic]

wish you had asked curtis, i have loads of 256x4 dip ram chips(i think rev 6 uses those?)

Hey mechy do you have DIP chips for a commodore a2058 board?