What the Amiga's start-up screen colours mean
When you switch it on, the Amiga tests its own hardware and shows the result as a colour. Knowing how to read those colours helps you work out where the problem is before you open the case.
Difficulty: EasyTime: 15 min
The normal sequence
On a trouble-free start-up, the screen quickly changes from dark grey to light grey and then to white, and the screen asking for a floppy disk (Kickstart 1.x) or the insert-disk animation (2.x and 3.x) appears. If there is a hard disk or a bootable floppy, it goes straight into Workbench or the game.
The error colours
If start-up stops on a colour, the colour tells you which test failed. These are the readings most widely used by the community; they confirm the area of the problem, not the exact part.
- 10Red: Kickstart ROM error (checksum). The ROM, the socket or the traces around it.
- 20Green: a problem with the Chip RAM or with Agnus, which controls it.
- 30Blue: a problem with one of the custom chips (Agnus, Denise, Paula).
- 40Yellow: the processor hit an exception before the system was ready, often because of an expansion or a badly seated chip.
- 50Black screen and no picture: it could be the power supply, the processor, the ROM, the CIA chips or the video cable itself. This is the case that most needs measurements.
First steps at home
Remove all expansions (trapdoor, side, accelerators) and test again: many error colours come from expansions. If you have the experience, carefully reseating the socketed chips, with the machine switched off, sorts out oxidised contacts.
When to bring it to us
If the colour stays the same with no expansions, the problem is on the main board. Tell us the colour and the model in your repair request: it is a valuable clue for the diagnosis.
Request a repairThese guides are for information. Working on old electronics carries risks: do it at your own risk, with the machine unplugged, and never open power supplies or CRT monitors. If in doubt, bring the machine to us.