Corrupted Diagrom Output

[Kepler]

Hi all,

I am attempting to repair a battery damaged A2000 and have stumbled across something I have never seen before, corrupted text from the output of Diagrom. See attached pictures.

IMG_20250216_120214.jpg (353.71 KiB) Viewed 2924 times

Regarding the machine, I have fixed several broken traces, checked every custom IC, re-read and followed some of the other A2000 threads on here...It does seem to pass those first four checks that are often mentioned. In fact, from the results of my logic probing on the CPU, there is activity on all the Data and Address lines. I also know the RAM is good as it is socketed so I have tested them.

IMG_20250216_120226.jpg (334.3 KiB) Viewed 2924 times

So, where do I look next?

[rubber_jonnie]

Ho @Kepler

For the sake of clarity, I've rotated your pics so they are easier to see for everybody, if you could do so before uploading that would be helpful, thanks.

Also one of the images was placed inline, the other was just attached. Please remember to place your images in line rather than leave them as attachments as the images sizes can show up differently if just left as attachments.

As for your issue, is it possible that you've got a problem with the serial port?

[Kepler]

Thanks. I will follow those points in the future.

It's possible that the serial port is faulty, I have not really checked that area yet...I am not even sure how I would.

[rubber_jonnie]

Thanks. I will follow those points in the future.

It's possible that the serial port is faulty, I have not really checked that area yet...I am not even sure how I would.

Either DiagROM or Amiga Test Kit allow for a serial port test, and one of them describes how to make the necessary dongle for testing the ports.

[Kepler]

I thought I would give an update on my progress over the last 10 days in which I have:

Removed and replaced all the RAM, U103-U106, U540-U541, U602-U605, U304-U305 (handles serial communication), RP101
Repaired 6 broken traces

...and after all that, I still have the same problem as before, a green screen and garbage in Diagrom.

Only 2 logic ICs have not been replaced (U600-U601)...which I will probably do at some point.

I am at a loss of what to do next?

[rubber_jonnie]

I thought I would give an update on my progress over the last 10 days in which I have:

Removed and replaced all the RAM, U103-U106, U540-U541, U602-U605, U304-U305 (handles serial communication), RP101
Repaired 6 broken traces

...and after all that, I still have the same problem as before, a green screen and garbage in Diagrom.

Only 2 logic ICs have not been replaced (U600-U601)...which I will probably do at some point.

I am at a loss of what to do next?

Can you boot from floppy at all? If so can you boot to Amiga Test Kit? Does the ROM work elsewhere? Are there any settings that are wrong in Putty?

Were you able to test the serial port?

[Kepler]

No, I only have a green screen with a Kickstart ROM. I have tried several. My Putty settings are correct.

I don't have a serial dongle tester.

[arkadiusz.makarenko]

You must have still some traces vias or sockets damaged.
It appears that you do have CPU and ROM lines working ok, as code is being executed, and at least some lines that support serial.

[Kepler]

I forgot to add, I have also replaced the CPU, ROM and Agnus socket.
I will go back and look for more broken traces...