exxos's Atari, Amiga & retro forum

Hi all,

My Amiga 2000 has stopped working...just produces a black screen. There is no battery damage and I have not found any broken tracks. I have tried all the custom ICs in a different board, all fine.
Diagrom doesn't produce an output on screen, in fact, the machine doesn't generate activity on the data lines with Diagrom but it does with my Kickstart 1.3 ROM?! Although, all data activity stops after 12-15 seconds with the 1.3 ROM.

The clock produces a 7.09 MHz signal.

I am not sure what to do next.

Might be worth working through the suggestions in this amibay post -> https://www.amibay.com/threads/amiga-20 ... een.19708/

Thanks.
I have tried most of what has been mentioned and unfortunately it has not made a difference. In most instances of this behavior, I would suspect a corroded pin or two on the CPU socket, but in my case, the pins are absolutely fine. As I mentioned, there has been hardly any battery damage and all the pins around that area generate a good connection with their connected ICs.

What I would really like is some form of logical fault finding guide centred around the boot process and what signals should be coming from which IC. But does such a guide exist?

You've tested all the reset side?

There is no output on serial port from DiagROM?

If it's absolutely dead i suspect clock/Power

BennehBoy wrote: 12 Jun 2024 13:49 You've tested all the reset side?

Could you elaborate on that please?

Tried posting this but I think exxos was still working on nginx...

Get your scope on pin 18 of the 68k (RESET pin), it should stay low briefly when powered on then get pulled up high. The low pulse is the reset circuit doing its job.

There is a lot of troubleshooting information readily accessible on the internet, beyond the scope of a quick answer from me I'm afraid.

Good luck and keep us posted of progress.

Another thread perhaps worth a read:

https://eab.abime.net/showthread.php?p=1402234

BennehBoy wrote: 12 Jun 2024 14:51 Tried posting this but I think exxos was still working on nginx...

Get your scope on pin 18 of the 68k (RESET pin), it should stay low briefly when powered on then get pulled up high. The low pulse is the reset circuit doing its job.

There is a lot of troubleshooting information readily accessible on the internet, beyond the scope of a quick answer from me I'm afraid.

Good luck and keep us posted of progress.

Yes, I understand. Pin 18 does start low and then go high as does _HLT.

Kepler wrote: 12 Jun 2024 15:25

BennehBoy wrote: 12 Jun 2024 14:51 Tried posting this but I think exxos was still working on nginx...

Get your scope on pin 18 of the 68k (RESET pin), it should stay low briefly when powered on then get pulled up high. The low pulse is the reset circuit doing its job.

There is a lot of troubleshooting information readily accessible on the internet, beyond the scope of a quick answer from me I'm afraid.

Good luck and keep us posted of progress.

Yes, I understand. Pin 18 does start low and then go high as does _HLT.

take a look at the CLOCK PIN 15 and check for a clock, then check pin 20 for a 700KHz clock (E). Finally check pin 6 for wiggling (/AS). If you see all those the CPU is running. Strongly recommend getting something on the serial port.