Amiga 3000T need help troubleshooting

[Castellen]

I've seen these symptoms a number of times before, and it's usually caused by a chip memory address fault.  See my previous post on this subject where I'd hypothesised this.  This latest clue adds plausibility.

From experience, it's most likely a fault in one of the DRAMs.  Address faults are tricky to isolate to a specific device, so the best bet is probably to replace the chip memory DRAMs with new or known good devices.  You'll need a good desoldering station as half of the DRAMs are soldered into the board in the A3000T.

And in case you've not done so yet, remove the socketed chip memory DRAMs and repeat the test as this will force DiagROM to use the bottom half of the memory.  If the problem remains, then you've got the options of attempting some very complicated address fault finding, or replacing the DRAMs.

Would be useful if you can post the serial (text) output from DiagROM or post a screen shot, I don't do YouTube.

[tlgrooms]

I have pulled all the socketed memory off of the board before running the above tests.  All the cards, drives and everything else.  It's barebones.  I'll run the tests thru the serial port tonight and post here.  Thanks again for the help and suggestions.

[Castellen]

Coincidentally, I just noticed that Chucky has been working on some memory address tests for DiagROM:
http://www.diagrom.com/index.php/download/

I've not tried it yet, but would certainly be worth a look in your case.  For the time being, you'll need to use the daily build until this feature makes it into to the 'stable' version.

[tlgrooms]

Attached is the link to the serial output from Diagrom 1.2.1. The 3000T only has the onboard ram in it, all other socketed memory has been removed.

I unfortunately don't have a way to burn my own roms. 

https://drive.google.com/file/d/1pmnlP343S1JPgVoClhnrVtaTL2zWdoXa/view?usp=sharing

[Castellen]

From the DiagROM output, there's quite obviously a chip memory problem.

For a start, it consistently reports:
  - Test of writing byte (even) $ff to $400 FAILED

If you're using a terminal in ANSI/VT220 mode, this will appear in red, to highlight the problem.



It then correctly reports the memory address range, and correctly decides on a base address of $ECCEA:
Startaddr: $00000400  Endaddr: $000FFFFF
  - Fastmemcheck skipped as we found chipmem
- Parallel Code $fb - Memorydetection done

  Using $000ECCEA as start of workmem (Base) 



But the base address is then somehow reported as $EEEEAAAA:

Detected Chipmem: 1024kB
Detected Motherboard Fastmem: 00kB
Basememory address: $000EEEEAAAA 

Of course there's no memory at that address, so it could never work with that.  It's more likely to be an issue with the string being written as EEEEAAAA instead of the expected ECCEA.


In fear of sounding like a broken record, this looks exactly like a chip memory fault, which is probably caused by one of the eight soldered in 256k x 4bit DRAMs being defective, but it's not easy to pinpoint which DRAM has the issue.  Fortunately they're not that hard to find new and were around $3ea when I last bought some.  Your cheapest and easiest route from here would be to buy eight new 256kx4 DRAMs in ZIP package, find someone local who is very good at through hole component soldering work, and get them to replace all 8 DRAMs.  Note that these parts are different from the 1Mx4 DRAM as used for A3000 fast memory.

As a source of DRAMs, contact Michael M (mechy on Amiga.org) who may have stock of these in America.  I can share his Email address privately if needed.



And FYI, I quickly ran DiagROM v1.2.1 in a good A1200 for a comparison of what to expect on a correctly working machine:

Code: [Select]

[With A1200, 2MB memory, DiagROM v1.2.1]

Garbage before this text was binary numbers: 1, 2, 4, 8, 16, 32, 64, 128, 240
5, 170 and 85
To help you find biterrors to paula. Now starting normal startuptext etc

Amiga DiagROM V1.2.1 - 16-Jul-20  - By John (Chucky/The Gang) Hertell


Testing if serial loopbackadapter is installed: <> NOT DETECTED
- Parallel Code $ff - Start of ROM, CPU Seems somewhat alive
    Checking status of mousebuttons for different startups:

    Set all Interrupt enablebits (INTENA $dff09a) to Disabled: Done
    Set all Interrupt requestbits (INTREQ $dff09c) to Disabled: Done
    Set all DMA enablebits (DMACON $dff096) to Disabled: Done

Testing if OVL is working: OK
- Parallel Code $fe - Test UDS/LDS line
  - Test of writing word $FFFF to $400 OK
  - Test of writing word $00FF to $400 OK
  - Test of writing word $FF00 to $400 OK
  - Test of writing word $0000 to $400 OK
  - Test of writing byte (even) $ff to $400 OK
  - Test of writing byte (odd) $ff to $401 OK
- Parallel Code $fd - Start of chipmemdetection

Addr $001F8400   OK  Number of 32K blocks found: $40
Startaddr: $00000400  Endaddr: $001FFFFF
  - Fastmemcheck skipped as we found chipmem
- Parallel Code $fb - Memorydetection done

  Using $001ECCEA as start of workmem (Base)

- Parallel Code $fa - Starting to use detected memory

Testing if serial loopbackadapter is installed: <> NOT DETECTED
Detecting if we have a working raster: DETECTED
Detected Chipmem: 2048kB
Detected Motherboard Fastmem: 0kB
Basememory address: $001ECCEA
As a very fast test of variablearea working this SHOULD read OK: OK!
- Parallel Code $f9 - Detected memory in use, we now have a stack etc
 - Doing Initstuff
 - Setting up Chipmemdata
   - Copy Menu Copperlist from ROM to Chipmem
   - Copy ECS TestCopperlist from ROM to Chipmem
   - Copy ECS testCopperlist2 from ROM to Chipmem
   - Fixing Bitplane Pointers etc in Menu Copperlist
   - Copy Audio Data from ROM to Chipmem
   - Do final Bitplanedata in Menu Copperlist
 - Initstuff done!

    Set Start of copper (COP1LCH $dff080): Done
    Starting Copper (COPJMP1 $dff088): Done
    Set all DMA enablebits (DMACON $dff096) to Enabled: Done
    Set Beam Conter control register to 32 (PAL) (BEAMCON0 $dff1dc): Done
    Set POTGO to all OUTPUT ($FF00) (POTGO $dff034): Done
- Parallel Code $f8 - Starting up screen, text echoed to serialport
Amiga DiagROM V1.2.1 - 16-Jul-20  - By John (Chucky/The Gang) Hertell



Doing ROM Checksumtest: (64K blocks, Green OK, Red Failed)
$5A39AC3E $C5724DFE $7C779F2B $00000000 $00000000 $00000000 $00000000 $006C00


CPU: 68EC20 FPU: NONE  MMU: NOT CHECKED

Checking for fastmem
Pressing left mousebutton will cancel detection (if hanged)

Checking if a 24 Bit address cpu is used: YES
 - Checking for Memory in 24 Bit area (NON AUTOCONFIG)
 - Checking for Memory in Ranger or Fakefast area


[scuzzb494]

I had a very similar problem with my 4000T. Same issues. I swapped over the accelerator and that wasn't working. And then I noticed a dodgy ribbon connector. The thing fell apart in my hand. I replaced both the ribbon and the floppy drive and like magic the machine booted. I had changed the jumper setting to take the MKII and so flipped it back and refitted the PPC. The boot on the floppy had caused the issue and now the PPC was working and the whole thing sprang back to life. I know you have disconnected the floppy and hard drive but maybe you need one or tother to get the juices flowing. I sense this is a simple seating issue if you have the card connected and you may need some Brasso. Don't rule out a combination of issues though.

I hate towers by the way. It's a gravity thing. I have an A1200 in a tower and she works fine for a while and then she stops. Just like your 3000T. I swear that all I do is reconnect all the ribbons, press on the buffered interface, press the flicker fixer and reseat the Blizzard including the SIMM and she fires up first time no problem. Lasts a few months and then stops. I just press a few connectors and she springs back to life. Same with an Ateo Concepts 4000d in the tower. Seriously hate them. I've thought about lying them flat on their side... but they really are way too big.

I have two A3000T machines. Never use them. Just saying.

[magnetic]

Boot the amiga and start hitting the CAPS LOCK key does it stop lighting after 10 clicks|?

[tlgrooms]

I don't have it hooked up right now but I do remember it would quit lighting after so many clicks.  I'm just not sure how many.

I do have replacement zip chips (and sockets) that are known good and working and replacement 74F245PC chips and sockets to replace as well but I don't know anyone who is willing to do the soldering work for me other than one fellow overseas which I don't want to ship the board that far as it's a huge board.  Really don't want to ship it anywhere, would prefer to take it to someone who could do the work so I'm just waiting until I can find someone within say 500 miles or so from me.

[magnetic]

The reason Im asking is that its a troubleshooting method. If it doesnt keep lighting its bad CPU

[tlgrooms]

That's the first I've ever heard of that.  Would Diagrom work with a bad CPU? It does come up with Diagrom.

[tlgrooms]

Still trying to get my 3000T going.  Have sent it to Chris Edwards to take a look at it.  He has replaced the onboard chip memory and it is still doing the same thing.  He has 2mb of chip memory in the machine now and it is only showing 1mb.   He has run diagrom again and is getting the following.  Here is his facebook post regarding it:

https://www.facebook.com/groups/CommodoreAmiga/permalink/10159059422414157/

This is it attached below.
Any suggestions would be greatly appreciated.

ok smart people, John Hertell wtf does this mean, 68030 a3kT 2mb chip, says 1 only, and this long thing from Diagrom 1.21 there is this fail... no kb mouse or nothing...
- Test of writing word $0000 to $400 OK - Test of writing byte (even) $ff to $400 FAILED
heres the bootup. braindead me. thx
Checking detected chipmem
@▒▒▒Ust detected chipmemal Memorytestrytests - kBFast: Base:
AA
Garbage before this text was binary numbers: 1, 2, 4, 8, 16, 32, 64, 128, 240, 15, 170 and 85
To help you find biterrors to paula. Now starting normal startuptext etc
Amiga DiagROM V1.2.1 - 16-Jul-20 - By John (Chucky/The Gang) Hertell
Testing if serial loopbackadapter is installed: <> NOT DETECTED
- Parallel Code $ff - Start of ROM, CPU Seems somewhat alive
Checking status of mousebuttons for different startups:
Set all Interrupt enablebits (INTENA $dff09a) to Disabled: Done
Set all Interrupt requestbits (INTREQ $dff09c) to Disabled: Done
Set all DMA enablebits (DMACON $dff096) to Disabled: Done
Testing if OVL is working: OK
- Parallel Code $fe - Test UDS/LDS line
- Test of writing word $FFFF to $400 OK
- Test of writing word $00FF to $400 OK
- Test of writing word $FF00 to $400 OK
- Test of writing word $0000 to $400 OK - Test of writing byte (even) $ff to $400 FAILED
- Test of writing byte (odd) $ff to $401 OK
- Parallel Code $fd - Start of chipmemdetection
Addr $00100400 OK Number of 32K blocks found: $20
Startaddr: $00000400 Endaddr: $000FFFFF
- Fastmemcheck skipped as we found chipmem
- Parallel Code $fb - Memorydetection done
Using $000ECCEA as start of workmem (Base)
- Parallel Code $fa - Starting to use detected memory
Testing if serial loopbackadapter is installed: <> NOT DETECTED
Detecting if we have a working raster: DETECTED
Detected Chipmem: 1024kB
Detected Motherboard Fastmem: 00kB
Basememory address: $000EEEEAAAA
As a very fast test of variablearea working this SHOULD read OK: OK!
- Parallel Code $f9 - Detected memory in use, we now have a stack etc
- Doing Initstuff
- Setting up Chipmemdata
- Copy Menu Copperlist from ROM to Chipmem
- Copy ECS TestCopperlist from ROM to Chipmem
- Copy ECS testCopperlist2 from ROM to Chipmem
- Fixing Bitplane Pointers etc in Menu Copperlist
- Copy Audio Data from ROM to Chipmem
- Do final Bitplanedata in Menu Copperlist
- Initstuff done!
Set Start of copper (COP1LCH $dff080): Done
Starting Copper (COPJMP1 $dff088): Done
Set all DMA enablebits (DMACON $dff096) to Enabled: Done
Set Beam Conter control register to 32 (PAL) (BEAMCON0 $dff1dc): Done
Set POTGO to all OUTPUT ($FF00) (POTGO $dff034): Done
- Parallel Code $f8 - Starting up screen, text echoed to serialport
Amiga DiagROM V1.2.1 - 16-Jul-20 - By John (Chucky/The Gang) Hertell
Doing ROM Checksumtest: (64K blocks, Green OK, Red Failed)
$5559999EEEE $CCC2222EEEE $7777777BBBB $00000000000 $00000000000 $00000000000 $0
0000000000 $000CCCC0000
CPU: 68030 FPU: 68882 MMU: NOT CHECKED
Checking for fastmem
Pressing left mousebutton will cancel detection (if hanged)
Checking if a 24 Bit address cpu is used: NO
- Checking for A3000/A4000 Motherboardmemory
- Checking for CPU-Board Memory (most A3k/A4k)
- Checking for CPU-Board Memory (most A1200)
(WILL crash with A3640/A3660 and Maprom on)
- Checking for Memory in 24 Bit area (NON AUTOCONFIG)
- Checking for Memory in Ranger or Fakefast area
IF This ROM is sold, if above 10eur+hardware cost 25% MUST be donated to
an LEGITIMATE charity of some kind, like curing cancer for example...
If you paid more than 10Eur + Hardware + Shipping, please ask what charity you
have supported!!! This software is fully open source and free to use.
33333FCCCC0444444444 00000DFFFFF111
180000 4EEEE7333348888E7777 FFFFFFEEEE42222AEEEE

[utukku]

I believe Chris has now fixed all of it for you now.