iMac mid 2011 21'5 no chime no boot fans spin

hi guys I have been given the above iMac from a friend


they said it wouldn't no longer boot so I took it apart and discovered just 2 of the diagnostic lights come on when you press the power button the 1st one is on as soon as you plug it in but the second one then comes and and stays on but there is no chime no nothing,



now if I remove the ram and boot it I get a single beep that means no ram if I remember correctly

I've tried the ram in my 27' iMac and its fine so its not the ram thats bad,


any suggestions on what I can check next ?

could it be a bad GPU ?

or even a bad logic board

thanks

I think your supposition that it might be a bad logic board or GPU may be correct. I guess while you have it apart you can always look for the obvious, but sometimes things that you can not see without diagnostic equipment could be the culprit.

I seem to remember that some 2011 iMacs had problems with a failing GPU so that might be where you can start. My old 2011 21.5" iMac is still going strong. I gave it to my granddaughter back in 2013 when I purchased a new iMac.

hi chscag I stripped the whole iMac down ordered a replacement PSU just incase it was somehow bad ??

anyway replaced the PSU and it fired up first go.

so would you say its a bad GPU ?

or Logic Board ?

or was it just the PSU that was bad ??

I did order a replacement Logic board off eBay but its EFI password locked can this be got around ? (or should I not ask this here please tell me if I shouldn't)

don't get me wrong the seller I had the logic board off has loads for sale they are a business here in the UK

thanks for any help

Jason

I did order a replacement Logic board off eBay but its EFI password locked can this be got around ? (or should I not ask this here please tell me if I shouldn't)

don't get me wrong the seller I had the logic board off has loads for sale they are a business here in the UK

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No problem asking here. As for the EFI password locked logic board, it's doubtful that you will be able to use it without removing the password lock. Older model logic boards were easier to remove the password lock, but newer models require special equipment only possessed by Apple.

If the logic board is by chance from an older model iMac (2011) you can probably remove the password lock. I'm going to let you do the googling to find the solution rather than post it here though. Let us know how it turns out.

Good luck with it.

hi again chscag


I did some research over the last day and its a mid 2011 iMac logic board so from everything I've read it can't be removed without apple doing so,


so ive contacted the seller I had the board from and they are sending me another that they assure me won't contain any locks and will be checked I've asked them if I should return the board I have in my possession now and they said no.

do you think thats normal practice ?

thanks

Did not the new Power Supply fix the machine not booting?

so ive contacted the seller I had the board from and they are sending me another that they assure me won't contain any locks and will be checked I've asked them if I should return the board I have in my possession now and they said no.

do you think thats normal practice ?

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Not normal practice, but I have seen that before even with larger retailers like Amazon. Anyway, that saves you the trouble of packing it up and sending it back to the seller and possibly incurring postage fees.

And given it's locked, the seller may not be able to unlock it either, so no reason to ask for it back.

hi guys yeah the new power supply did resolve the issue

but a spare logic board is always good

hi guys so after a few days of using the iMac its now booting with no display at all I get the chime but thats it the keyboard and mouse are responsive,

but there is no video at all.

on the built in display or an external Cinema Display

ive changed the GPU already but I'm not getting anymore than 2 lights on the logic board out of the 4

thanks