Imac 27 screen problem?

[Wek]

Hi

We have an old Imac 27 inch. Yesterday the screen made these (picture) lines and no matter what I do, I cant make them disappear? any advice?

 

[Cruz3LT]

More info would be helpful.

 

[Wek]

More info would be helpful.

Well - the Mac is running, but its hard to use, because of phones coloured lines. I have starte in safe mode, and ordinary mode, but it's the same result.

 

[Cruz3LT]

I mean the year, processor and gpu.

 

[TwoH]

Very high chance of GPU failure - going by the picture.

 

[Allyance]

Strange lines are not parallel, if there was a problem with GPU or display, would lines be parallel? Reflection?

 

[TwoH]

They are parallel?? But on second look - he's able to boot into his iMac. Do you have an external display to test if it's display or GPU?
Same issue on an external: GPU
No lines on an external: LCD

 

[Cruz3LT]

These are signs of a GPU on its way out, not fully failed. I asked the op which model to see if it is one of the ones with known GPU issues.

 

[TwoH]

These are signs of a GPU on its way out, not fully failed. I asked the op which model to see if it is one of the ones with known GPU issues.

It literally is a sign of GPU... But yeah, wait for OP to respond, I guess

Edit: whoops didnt see you said it IS -- so yes, either way, GPU needs replacing

 

[mikehalloran]

I mean the year, processor and gpu.

Replace the NV RAM battery. I’d say how but the above was never answered.

If the problem persists, then look at the GPU.