Platforms: Amiga
Problem: Amiga system will not boot. Screen flashes colors or keyboard lights flash.
You may notice that when you turn on or reset your Amiga a few different colors flash by. These actually mean something. Here you go:
RED Bad ROM
YELLOW CPU Exception Before Bootstrap Code is Loaded
GREEN Bad Chip RAM or Agnus (check seating of Agnus)
BLACK No CPU
WHITE Expansion passed
GREY CPU Passed
Constant white is failure of CPU.
Or as taken from the Amiga 4000 Service Manual:
Passed Test Light Gray Initial hardware configuration tests passed.
Initial system software tests passed.
Final initialization test passed.
Failed Test Red ROM Error - Reseat or replace
Green CHIP RAM error (reset AGNUS and re-test)
Blue Custom Chip(s) Error
Yellow 68000 detected error before software trapped it (GURU)
The system performs the following test sequence:
1. Delays beginning the tests a fraction of a second to allow the hardware to stabilize.
2. Jumps to ROM code in diagnostic card (if found)
3. Disables and clears all DMA and interrupts.
4. Turns on the screen.
5. Checks the general hardware configuration.
If the screen remains a light gray colors and the tests continue, the hardware is OK.
If an error occurs, the system halts.
6. Performs checksum test on ROMs.
If the system fails the ROM test, the screen display turns red and the system halts.
Keyboard
One Blink ROM Checksum failure
Two blinks RAM test failed
Three Blinks Watchdog timer failed
Four blinks A short exists between two row lines or one of the seven special keys
(not implemented)
Five Blinks Your keyboard has become nuclear. RUN!