Can an iMac chime if the logic board is bad?

[Crystaleyes]

Hi all.

A friend has a 2011 iMac which chimes (and apparently plays music) but was told by a technician that the logic board needs replacing.

The screen stays black, but music apparently plays when the keyboard 'play' button is selected.
A bit beyond my experience...??!!??

I was under the impression that bad logic boards don't give the Apple chime.

Anyway, they are bringing it over tomorrow where I'll check the diagnostic LED's to get a better idea. Seems more like a PSU, GPU or inverter problem to me.

A bad logic board should just have one LED no?


I would love to hear your thoughts

[Crystaleyes]

Re: Can an iMac chime if the logic board is bad?

Surely if an iMac performs the startup chimes, then the logic board is receiving power and has performed the necessary basic function tests?

That would give 'two' diagnostic LED's. My experience is limited but I have never know a 'bad' logic board to play the chimes.

Three LED's would indicate that the GPU is also communicating fine.

No-one out there has any experience with this?

[reformatt]

Re: Can an iMac chime if the logic board is bad?

The chime means the board has completed POST and booted. So likely a display related issue. Graphics card failures are pretty common on these pre-2012 iMac's so check status LED's. Also pretty sure these displays are also fluro backlight rather than LED...can be bad cables or failed inverter but my money is on the graphics card.

They are such a hassle to work on, and given it's age very few $$$ to be made on spending a lot of time on.

[Crystaleyes]

Re: Can an iMac chime if the logic board is bad?

Hi Reformatt

I would agree that it is most likely a GPU or even didplay issue.

In the end I didn't get to see the iMac but thanks for the input