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Re: A2000 Replica Build

Posted: Sun Feb 09, 2020 5:00 am
by grshaw
Hey there.

Yes - that's right. Solder the leg off the capacitor to the leg of the resistor.

Re: A2000 Replica Build

Posted: Thu Feb 13, 2020 3:38 pm
by nadoom
@grshaw

Not sure if you have fixed your green black screen issue.. but I am getting the same issue here as well.. since i completed the build.

Occasionally on a cold boot I will get to kickstart and even load deluxe paint 3. After that I Get green 11 flashes of the power and a black screen ( which is a reset )

I've tested the Agnus in my A500, replaced the Gary and swapped ram from my working A500++, let me know if you are still having an issue because if so we are in the same boat!

Interestingly when I sprayed dust off and cooled down all the chips I was able to cycle the power and get the kickstart to appear more regularly..

One more thing I noticed is that U103 -U106 get a bit warm. I swapped the SN74LS373N's with the ones in the A500++ and its the same ( the A500 uses 244's rather than SN74F245N's) so I couldnt swap them but i am thinking the problem is elsewhere.

Re: A2000 Replica Build

Posted: Thu Feb 13, 2020 4:49 pm
by nadoom
Ok I am in bizzaroland right now..

I was getting Green screen.. grey screen.. yellow screen even..

Then I sprayed some compressed air and chilled the whole thing and boom its boots.. any hardware gurus know what this could be?

Thanks

Re: A2000 Replica Build

Posted: Sat Feb 15, 2020 9:44 am
by grshaw
Not sure if you have fixed your green black screen issue.. but I am getting the same issue here as well.. since i completed the build.
No - unfortunately not. I think that my troubleshooting skills may not be up to the task. Acill has kindly offered to take a look at my board. To be clear, I don't think there is anything wrong with the PCB. It's likely to be my dodgy soldering. However, Acill has agreed to take a look anyway. What a legend. :D

Re: A2000 Replica Build

Posted: Sun Feb 16, 2020 5:55 am
by nadoom
@grshaw ahh excellent I'm going to go over my shoddy soldering today and hope that fixes it.. it seems heat expansion related because of the way it works when I cool it, but I am a noob what do I know 😂. but please tell me what acill comes up with 👍🏽👍🏽👍🏽

Re: A2000 Replica Build

Posted: Sun Feb 16, 2020 6:37 am
by grshaw
Sure. Will do. :D

Re: A2000 Replica Build

Posted: Sun Feb 16, 2020 5:54 pm
by nadoom
Here's a strange one for you..

With a 2.04 rom i get green screen most of the time.. and always when i reboot..

With a 1.3 rom i never get a green screen and resets are always successful

Any one know whats up with that?

Re: A2000 Replica Build

Posted: Wed Feb 19, 2020 6:05 am
by grshaw
Have you tried the 2.04 ROM in another ( known working ) machine? Perhaps it is faulty? Also - sounds like you need to try booting with DiagROM. Perhaps you have some kind of intermittent fault. Hopefully DiagROM would help to diagnose where the fault is.

Re: A2000 Replica Build

Posted: Sat Feb 22, 2020 4:22 am
by nadoom
Hi grshaw , I was getting some strange stuff last night with diagrom installed..

memory was slowly declining on every reset starting with 1024kb (green flashing screen)
992kb ( red and green flashing)
128kb (more red and green flashing)
No boot garbledmess.

However..

The buster chip I got on Ebay arrived this morning and having plugged this in and we have a working A2000 hasn't green screened yet (Please lord keep it that way) just going to leave it up and reset a few times to see what happens. so maybe the buster is required?

Disk drives are ticking but not working properly this might be CIA related.. <- this was actually caused by me putting the wrong GPT in Q301 it calls for a 3904 not a 3906, I salvaged one from a murdered a500+ so its working well now.

Re: A2000 Replica Build

Posted: Mon Feb 24, 2020 7:26 am
by grshaw
The buster chip I got on Ebay arrived this morning and having plugged this in and we have a working A2000 hasn't green screened yet (Please lord keep it that way) just going to leave it up and reset a few times to see what happens. so maybe the buster is required?
Wow. That's awesome news! Sounds like my advice was wrong. Sorry if it sent you down the wrong path.