Amiga 3000 repair Faqs

[Prime]

I am trying to gather all the FAQs for troubleshooting the Amiga 3000. Please answer them if you are sure of the answer to help others out as well.
Here are some basic questions:
When I say "run" I mean see a kickstart screen of some kind.

#1 Can the Amiga 3000 run without the daughter board?
No - already established

#2 without a floppy drive?

#3 without a hard-drive?

#4 without a mouse?

#5 without a keyboard?

#6 without the battery?

#7 Can you buy the weird 15 pin molex type power connector anywhere to make a longer power supply cable?
Knowing Amiga & Commodore this is probably proprietary.

#8 Is there a way to test for bad roms?

#9 Can you use other Amiga Model parts to use in the 3000, CIA's, Denise, Paula, etc....

#10 Can you use other Amiga Hardware, say an A500 internal floppy on a A3000?  (I don't care if it mounts or fits (we know it wont) I just care if it would actually boot a floppy)

Almost everything I have read states that Amiga 3000's are bulletproof. I am going CRAZY :crazy: trying to fix one that worked great, till I opened it up, now I get no video, and no boot.
Also, the cap lock light works for about 12 times then dies, so the CPU is not receiving data from the CIA.

AHHHHHHHHH HELP.





  :crazy:  :crazy:  :crazy:  :crazy:  :crazy:

[Prime]

Also...
The computer doesn't require any fast RAM to boot.

- The Zip sockets are filled to the brim, it is a LOT of work to remove them all, maybe I will try that last.

Reseat all the socketed ICs, socket connection problems can cause non-booting and unstable operation.

- I re-set all the major proms

Check you have correct clock distribution throughout the computer, this mainly comes from U103.

- clock signal present on all the chips I tested (I am not sure where the 68030 clk is and I dont want to short it out by guessing)

Check the various reset lines are high (5V).
- Yes

Check FAIL_ is high (5V).
- Dont know where FAIL_ is


Try disabling the FPU using the.
- Did not work

Check the ROMs are being read by using an oscilloscope, measure on the ROM output enable pin, 20, going low during most of the CPU read cycles.
- Pin 20 goes high the entire time


Check you have a valid TICK signal at J350.
-TICK signal present @ J350.

I am about ready to throw it in the trash :pissed:.

Thanks

[Prime]

Thanks Castellen,

I will check the Rom pin 20 for going low with my works nice digital Oscilloscope, I didn't realize the signal was going to be that fast. So I will set it to trigger on low.

I will likewise check the FAIL_ on the RTC and Gary.

How hearty are the A3000 motherboards? When I un-soldered the battery maybe I damaged one of the planes? Or maybe I destroyed a trace? The top and bottom plane of the motherboard look great.


I will let you know,
Thanks

[Prime]

Castellen,

You are a treasure trove of information!

The battery leakage was actually very minimal, there are a couple of green leads which I will look at closer.

The ROM0 U180 never goes low, I used a 300Mhz digital scope.
It stays high and that's it.

I will check for green corrosion around neighboring chips. Paula and Denise are pristine and the sockets they reside on are as well.

Do you have a pinout for the Fat Gary? I am not sure where pin 1 is on that plcc.

[Prime]

Castellen,

In your A3000 booting problems you reference:

BLACK (No video) = R406 or R215 open R406=1 ohm R215=4.7 ohm Agnus or Denise defective

I cannot find either of these resistors on the motherboard, can you tell me what they are close to, or the general vicinity?

Thanks,

[Prime]

Plaz wrote:
#7 - Yes. I bought the parts and built on for my 3000.

I can try to find the supplier and part numbers if you like.

It is not an easy task to make one of these though.


Plaz

It would be awesome if you could get me the part# thanks.