Mid 2011 27inch iMac Repair help

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
hey everyone, i currently work in the IT department at a large local hospital and there is a junk area where the various departments throw away old junk computers and stuff of that sort,

well yesterday i was going through the junk and came upon a 27inch mid 2011 imac with no hdd or ram or hdd caddy but i do have ram for it right now,

but it will not power on, i showed it to our mac guy and he says the power supply is dead which makes sense, however i am having a hard time finding a replacement,

most of the ones i do find are for a 2009-2010 27inch imac and i doubt it would work, but does anyone know where i can find one for a good price or am i out of luck?

also i have seen some threads on the net of some people upgrading the video card to one with a gig of memory is it possible to do that to this one aswell?
 

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
OK I bought the correct power supply and got it hooked up however I still get no lights or fans and there is power going to the power supply, anyone got any ideas I can try?
 

macthefork

macrumors 6502
Feb 2, 2013
467
7
What testing was done to determine it was the power supply. There are four diagnostic LEDs on the logic board near the bottom. (might be behind a display cable). Do any of the diagnostic LEDs light up when it's plugged in. One should be lit if the iMac is plugged in and it's getting power from the power supply. Do any light up when you push the power button? Two LED's show the Logic board is powered and on.
 

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
What testing was done to determine it was the power supply. There are four diagnostic LEDs on the logic board near the bottom. (might be behind a display cable). Do any of the diagnostic LEDs light up when it's plugged in. One should be lit if the iMac is plugged in and it's getting power from the power supply. Do any light up when you push the power button? Two LED's show the Logic board is powered and on.
no led's no fans nothing
 

macthefork

macrumors 6502
Feb 2, 2013
467
7
If no diagnostic LEDs light up when it's plugged in, then it still has a bad power supply, or it's not connected properly. Even one LED would show that there is a trickle charge going to the Logic board.
 

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
If no diagnostic LEDs light up when it's plugged in, then it still has a bad power supply, or it's not connected properly. Even one LED would show that there is a trickle charge going to the Logic board.
what if the logic board is bad? would that cause no fans or leds?
 

macthefork

macrumors 6502
Feb 2, 2013
467
7
I would think that even with a bad logic board, at least one LED would light since the power goes directly to it. The second LED is for showing the Logic board is powered and working. Do you see any burned out areas on the logic board?
 

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
I would think that even with a bad logic board, at least one LED would light since the power goes directly to it. The second LED is for showing the Logic board is powered and working. Do you see any burned out areas on the logic board?
No I even took it out and looked all over and smelled it to see if it had a burnt smell and nothing
 

AppleNewton

macrumors 68000
Apr 3, 2007
1,697
83
1 Finite Place
If you want to try and find a PSU for the 2011 iMac the PN is 661-5972

The one from the 2009/2010 iMac *may* work..theyre all 310W PSUs, and nearly identical the only different was the 2009 had a dual-core cpu and required a different PSU if I'm not mistaken.
 

dr.oid

macrumors newbie
Aug 11, 2013
8
0
Learned useful things during my repair carrier: old Macs are like old dogs they are getting nasty problems as they get older ➔ No Power On Self Test, no chime usually means dead power supply ➔ cheap solution, memory module error ➔ just replace it, dead logic board ➔ hard times big sucks, dead video card ➔ like the previous one, if it's a minor repairable error you're a lucky man :D
 

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
If you want to try and find a PSU for the 2011 iMac the PN is 661-5972

The one from the 2009/2010 iMac *may* work..theyre all 310W PSUs, and nearly identical the only different was the 2009 had a dual-core cpu and required a different PSU if I'm not mistaken.
i can hear a hum from the one i bought when its plugged in and when the old one is plugged in its still getting some juice as when i first picked it up i accidentally shocked myself on it

Learned useful things during my repair carrier: old Macs are like old dogs they are getting nasty problems as they get older ➔ No Power On Self Test, no chime usually means dead power supply ➔ cheap solution, memory module error ➔ just replace it, dead logic board ➔ hard times big sucks, dead video card ➔ like the previous one, if it's a minor repairable error you're a lucky man :D
either the logic board is so dead that no power is getting through it or there is a wire messed up some where between the power supply and logic board to where im not getting anything
 

luke9511

macrumors member
Original poster
Mar 23, 2015
42
0
ok so i was working on the imac again and was staring at the logic board when i saw the following, is this fixable? or would i have to buy a whole new logic board?

 

macthefork

macrumors 6502
Feb 2, 2013
467
7
when a component like that goes on the board, it can cause other local sensitive components to burn out also. Likely a new board is needed.