Problem with my amiga 4000

[Nek3d]

I have a perfectly working amiga 4000 D /040 with 3.1 ROMs and a week ago I tried to upgrade the ROMs to 3.2.2. I used chips 29F1615, 27c800, and 27c400 all attempts failed to boot. I got black screen and the power led was flashing. I put back the original 3.1 ROMs and still didn't boot (but the led was not flashing). Then I used diagROM and it worked.The amiga passed all tests!. (I am certain that I burned the right ROM images for amiga 4000 and used the right sockets for Hi and Low ROMs). Today I replaced the ROM sockets with new ones (better quality than originals). I tested all ROMs and got the same results: Black screen, Power Led flashing, DiagROM works and passes all tests. The only difference is that during a test boot I saw a yellow screen for 1-2 sec. Could not reproduce that again! I have a few notes that I need help with:

1) With a thermal camera I checked all chips and the BUSTER 11 is cold. (With Riser Board and without it, buster is cold, is that normal? Buster is soldered, I checked that the pins are OK and give power to the chip)
2) On the Riser Board's right side the resistor arrays get too hot (check IR photo), Is that normal?
3) On the Riser board I checked that 5V have 0.014 diode mode reading / 10ohm resistance to Ground. Is that normal?
4) Does the DiagRom need BUSTER to be working? I think the Buster chip is not checked by Diagrom...

Any ideas what to check next?

 

[Boing-ball]

Question.

How did you remove the ROMs? By chance a screwdriver perhaps?

 

[amienslaver]

I used chips 29F1615, 27c800, and 27c400

Did you use the same .bin files for all these chips? I mean, they are of different size. Any chance to test ROMs are functioning on another machine?

Today I replaced the ROM sockets with new ones (better quality than originals). I tested all ROMs and got the same results: Black screen, Power Led flashing, DiagROM works and passes all tests.

Did you check the flashing code? In general, yellow screen does not necessary a problem with Buster, it can also be a problem with memory access (i.e. bad contact with SIMM). As you changed ROM sockets, did you trace that you have continuity from each pin afterwards? A trace could have cracked while you were replacing them.

 

[tadeo80]

Check the memory chip socket and its paths very carefully

 

[Nek3d]

Question.

How did you remove the ROMs? By chance a screwdriver perhaps?

No, with a custom removal tool. It works perfectly.

 

[Nek3d]

Check the memory chip socket and its paths very carefully

You mean the 5 SIMM sockets for CHIP and Fast RAM? But when I install DiagRom it runs and shows the correct memory. (2 chip, 16 Fast)

 

[Nek3d]

Did you use the same .bin files for all these chips?

Yes same files, but on 27c800 chips I burned the file on both sides since the chip has double size capacity

 

[Nek3d]

did you trace that you have continuity from each pin afterwards? A trace could have cracked while you were replacing them.

I must check each pin then. I only looked at them under a microscope and they seemed OK.

 

[Nek3d]

Did you check the flashing code?

What flashing code? I searched for Power Led flash codes and found nothing..

 

[tadeo80]

You mean the 5 SIMM sockets for CHIP and Fast RAM? But when I install DiagRom it runs and shows the correct memory. (2 chip, 16 Fast)

You mean the 5 SIMM sockets for CHIP and Fast RAM? But when I install DiagRom it runs and shows the correct memory. (2 chip, 16 Fast)

I had a similar situation. Yellow or black screen and flashing diode. The chip memory path was broken. Almost no diagrom will detect a buster failure. You can run the diagrom without the daughter board inserted
Remove the ram chip (not fast ram), start it and see if the screen turns yellow.

 

[Nek3d]

I had a similar situation. Yellow or black screen and flashing diode. The chip memory path was broken. Almost no diagrom will detect a buster failure. You can run the diagrom without the daughter board inserted
Remove the ram chip (not fast ram), start it and see if the screen turns yellow.

I suspect that the yellow screen (only for 1-2 sec and happened only once) is because of not properly seated RAM chip. Later I reseated all RAM chips and I never saw a yellow screen again. But I always get black screen and flashing power led. I will try what you suggest.

 

[Boing-ball]

This may help. Mentions LED blink errors but for A1000 and A2000 systems

🔨 -- Amiga Error Colours, Blinks and Guru Codes --

Here is some info I gathered from around the web concerning your Amigas boot sequence, and the error codes which your computer will provide to help pinpoint…

www.lemonamiga.com

 

[amienslaver]

I must check each pin then. I only looked at them under a microscope and they seemed OK.

They sometimes look OK even under the microscope, especially if you have a non-binocular one. Checking traces on all pins of ROM sockets at least can reduce the search space for the cause of the problem. Then, as suggested, check memory paths. Hafnium diagnostic board can help you to check memory slots quickly, but I'm not sure it can be shipped to EU directly.

 

[HomeLate]

I can vouch for Hafnium's diagnostic board. I used it successfully to check memory slots in battery damaged A4000's and RiscPC's.

 

[Synapse70]

When asked RetroSupplies last week about a delivery outside UK, it was still a "No".

 

[amienslaver]

When asked RetroSupplies last week about a delivery outside UK, it was still a "No".

It is clearly stated on his website that he is not shipping to EU due to recent changes in law. So, you need to find a way to bypass it, like parcel forwarding services.

 

[Nek3d]

It is clearly stated on his website that he is not shipping to EU due to recent changes in law. So, you need to find a way to bypass it, like parcel forwarding services.

I have a friend in the UK and I always send the amiga stuff to him!

 

[Nek3d]

I had a similar situation. Yellow or black screen and flashing diode. The chip memory path was broken. Almost no diagrom will detect a buster failure. You can run the diagrom without the daughter board inserted
Remove the ram chip (not fast ram), start it and see if the screen turns yellow.

I get your point, but how can I have a problem with the Chip or fast ram since I run DiagRom and checked the memory? Diagrom recognizes chip + Fast Ram normally and I passed the memory tests..

 

[amienslaver]

I get your point, but how can I have a problem with the Chip or fast ram since I run DiagRom and checked the memory? Diagrom recognizes chip + Fast Ram normally and I passed the memory tests..

Very easy. It depends on memory access patterns as it defines which lines on SIMMs are active and in what sequence.

 

[Nek3d]

Very easy. It depends on memory access patterns as it defines which lines on SIMMs are active and in what sequence.

So it's possible that even if diagrom ram tests are successful the memory sockets can still not work properly 100%?