Amiga Boot-up Screen Colors and System Error Checklist

[intric8]

When you boot up your Amiga you are always greeted with a series of flashing screen colors. On most days the screen will change from dark gray to a couple lighter shades then white before marching on. On bad days, it flicks over to an actual color of the rainbow, each with its own heart-stopping meaning.

What do those colors mean? And what is the Amiga doing during the boot-up process in the first place?

The following is a collection of ancient and excellent information compiled from various sources.

During boot-up, the Amiga is going through a series of system checks and routines.

1. Clear all chips of old data
2. Disable DMA and interrupts during the test.
3. Clear the screen.
4. Check the hardware ....checks to see if 68000 is functioning.
5. Change screen color.
6. Do a checksum test on all ROMS.
7. Change screen color.
8. Beginning of system startup.
9. Check RAM at $C0000 and move SYSBASE there
10. Test All CHIP RAM.
11. Change screen color.
12. Check that software is coming in ok.
13. Change screen color.
14. Setup CHIP RAM to receive data.
15. Link the libraries
16. Check for additional memory and link it
17. Turn the DMA and interrupts back on.
18. Start a default task.
19. Check for 68010, 68020, 68881 or other processor upgrades.
20. Check to see if there is an exception or processor error
21. If so do a system reset. 

During this system test the Amiga is sending vital information to the
screen with colors. If the system checks out ok, you will see the following
sequence that you have seen so many times.
 
DARK GRAY:  The initial hardware tested OK. the 68000 is running and the registers are readable.
LIGHT GRAY: The software is coming in and seems OK.
WHITE: The initialization test have passed.

The failure mode screen colors:

• Turquoise (0x0CC) (A1000 only): RAM failure in the Kickstart WCS
• Green (0x0F0) error in the lowest 256 bytes of Chip RAM. Possible causes, defective CIA-A IC or defective Agnus IC.
• Yellow (0xFE5) an unexpected processor exception before the appropriate system failure message was prepared. This could mean defective hardware or an attempt to access a RAM address where no RAM exists.
• Red (0xF00) invalid KickStart ROM checksum.
• Magenta (0xF0F) single-task or cold-start initialization failed.

Another listing of screen color interpretations:

RED	Kickstart ROM error	Two ICs in A1200, A3000, A4000
BLUE	Custom chip problem	Denise Paula Agnus
GREEN	RAM error
YELLOW	Above problems combined
LIGHT GREEN	CIA (U7/U300) problem
BLACK	CIA (U7/U300) problem	If not booting
DARK GRAY	Hardware tested OK
LIGHT GRAY	Software tested OK
LIGHT GRAY	CIA (U8/U301) problem	Stops at gray, CIA defective
BLACK/STRIPES	ROM or CIA
No video	R406 or R215 open R406=1 ohm R215=4.7 ohm
Video scrambled	Agnus or Denise defective

If the Amiga caps lock key LED blinks repeatedly at boot up, another series of error messages must be consulted:

• One blink: keyboard ROM checksum error
• Two blinks: RAM failure
• Three blinks: watchdog timer failure

If something is wrong with your system, you may see the following:

• RED: Error was found in ROMS.
• GREEN: Error found in the CHIP RAM.
• BLUE: Error was found in the custom chips.
• YELLOW: If 68000 found an error before the error trapping software (GURU) was running.

 The Keyboard has it's own processor, RAM and ROM. A selftest is performed
on power-up in the following sequence.

1. Performs checksum on ROM's
2. Checks 64 bytes of RAM.
3. The timer is tested.
4. Performs handshake with computer and gives results of self-test.

If the keyboard does not pass the test it will notify you that it is not
working properly. This information is indicated with the blinking of the
CAPS-LOCK light.

• One Blink:    Keyboard ROM check failed.
• Two Blinks:   Keyboard RAM checked failed.
• Three Blinks: Watch dog timer failed
• Four Blinks:  A short between two row lines or special control keys.

[LambdaCalculus]

Excellent and thorough post! This should be made a pinned post, as it's super useful to all Amiga users.

[intric8]

Not a bad idea. I've had to search for it a few times myself already. Done!

[mattsoft]

Nice compilation. Any idea what a never-ending flashing power light means?

[intric8]

Is this to do with your Wicher 500 experiments?

In the past I'm pretty sure I'd read flashing LEDs having something to do with Paula clashing with certain software. But I assume you mean from a stuck boot-up.

Like, does just your power light flash and nothing else happen?

[mattsoft]

Is this to do with your Wicher 500 experiments?

In the past I'm pretty sure I'd read flashing LEDs having something to do with Paula clashing with certain software. But I assume you mean from a stuck boot-up.

Like, does just your power light flash and nothing else happen?

Yeah, black screen, flashing power light, nothing else. I got it with the Wicher in a stock 1000. I can't find anything conclusive on this.

[intric8]

I would contact the creator directly. In fact, I did a few days ago (and after your tests, have cancelled my order for the Wicher at amigastore.eu, which they refunded today).

My conversation over the weekend, with Artur Gadawski:

Me: Does your software for the Wicher board run under KS 1.3?

Gadawski:

Now running only WicherDegrader under Kick1.3.
Other software requires minimum kickstart 2.05 (37.350)

Me: Once set, will the CPU stay at the desired speed after a reboot?

Gadawski:

Card configuration is maintained until power is turned off (if jumper 1 or 2 is removed.
If jumper 1 or 2 is set, after reset it is always set frequency from jumper.

I bet if you contact him directly, he'll try to help.

That card must be jamming it right at the ROM stack, before it can even get started.

[A1-X1000]

Excellent and thorough post! This should be made a pinned post, as it's super useful to all Amiga users.

+1

[clam wattson]

Thanks for compiling this info!

I have an Amiga 500 which sporadically displays the blinks error codes on the CAPSLOCK key. Generally this happens on cold boot and will sometimes go away after a few power cycles. The error code presented varies.

I have the means and ability to replace the keyboard controller (MOS 6570-036), but I don't want to go that route without exhausting other avenues.

The board appears to be stock. Has anyone seen this pattern before?

Should I recap first? Perhaps switch the even and odd CIAs? I have the ability to do these things, but figured I'd ask here before doing anything too invasive.

[StoneOakvalley]

Hi all,

The RED color seems also to be related to the Denise chip, as I experienced here.

My fix was to replace it completely, but my Amiga 500 1.2kick had also a bad seating og the Fat Agnus as well.

Regards Stone Oakvalley