amiga 4000 not displaying picture

[amiga4000freak]

If i plug there mouse in there screen flickers when i move there mouse around

[Digiman]

I would guess Lisa chip is gone if replacing chip ram doesn't fix it.

[gertsy]

I'd suggest hoping off the bus.

[amiga4000freak]

im 90% certain that there rom chips have failed.

Are there rom chips different in an amiga 1200?

[Karlos]

im 90% certain that there rom chips have failed.

Most ROM initialisation failures should result in the "red screen of death".

Are there rom chips different in an amiga 1200?

As far as I know, yes.

[amiga4000freak]

Is that there graphics chip?.
Also can it be repaired it looks like its there same has my 1200 chip set
Could i use a graphics card instead?.

[Karlos]

Ok, can you check your system motherboard? Make sure you check the area around the battery and also check for leaking capacitors. The batteries in A4000's are notorious for leaking after all these years.

Make sure you earth yourself before probing around in there. You don't want to add ESD to whatever malaise is affecting it presently.

[amiga4000freak]

battery was removed by previous owner and there is no sign of any leaks of acid, the board is very clean

[amiga4000freak]

It did work at first but it was not displaying all colours when i attached my amiga 1200 hard drive 3.5 an only got a few colours since then it has been showing a grey screen.

[Karlos]

It did work at first but it was not displaying all colours when i attached my amiga 1200 hard drive 3.5 an only got a few colours since then it has been showing a grey screen.

When you said the display flickers on moving the mouse, if the hardware was broken I wouldn't expect that.

Can you get a shot with a camera or something?

I wonder if it has booted into a displaymode you can't see properly.

[amiga4000freak]

I used my amiga 1200 just to check and monitor ok

[Karlos]

I used my amiga 1200 just to check and monitor ok

I'm sure the monitor is fine, I'm actually wondering about the settings on your 4000.

What happens if you power on from cold whilst holding down both mouse buttons for about 30 seconds?

Do you get into a working early startup screen?

[amiga4000freak]

no m8

It goes dark then a light grey again

[tone007]

Remove and reseat the CPU board!

[amiga4000freak]

already done that a few times no change m8

[tone007]

Darn.