A4000 boot error colours - Magenta?

[danbeaver]

By Magenta do you mean purple?  Red = boot ROMs, Blue = custom chips, and Green = Chip ram. These are the initial colors on cold boot. Only OS 4.1 uses a light pinkish purple that I would call Magenta.

Could your monitor signal be set to clarify between Red and Blue?

[danbeaver]

On  a positive note the fact that it occasionally works indicates a likely intermittent contact issue; often they work when things heat up and metal expands or when you wiggle or jiggle a part or connection.

So reseat EVERYTHING and if it is not shiny use a fine emery board to get rid of oxidation; I use an eraser on gold card connectors. For things like cables that feel loose, use a fine set of needle nose pliers to tighten Molex pins and such. There is also sold through cyberguys a Deoxit spray to improve contact.

With patience and changing one thing at a time you might ne able to define what is at issue -- not likely you CPU from your scenario, so look to the motherboard and connections there

[danbeaver]

On  a positive note the fact that it occasionally works indicates a likely intermittent contact issue; often they work when things heat up and metal expands or when you wiggle or jiggle a part or connection.

So reseat EVERYTHING and if it is not shiny use a fine emery board to get rid of oxidation; I use an eraser on gold card connectors. For things like cables that feel loose, use a fine set of needle nose pliers to tighten Molex pins and such. There is also sold through cyberguys a Deoxit spray to improve contact.

With patience and changing one thing at a time you might ne able to define what is at issue -- not likely your CPU from your scenario, so look to the motherboard and connections there

[danbeaver]

Yes contact cleaner is best if you have it; Isopropal Alcohol will remove grease but does not reduce the oxidation. Acid will dissolve it (citric or acetic) and sulfite compounds will actively reduce it back to its metal base.

Intermittent contact issues might be caused by a failing capacitor.

[danbeaver]

Well it sounds like motherboard is fixable, you might have to get some work done on the CSPPC like replace a socket or some  capacitors. I would make the CSPPC my priority (they are my best Amiga addition next to the Deneb)