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Jimmy-Chivas

macrumors member
Original poster
Aug 22, 2022
31
14
Okay so, got my paws on a 2009 27" (for what it's worth, Chassis serial: QP01403J5RU) for 20 bucks.
Specs are below.

Unit powered up fine, had never been serviced and was a total dust bucket. Worst I have ever seen. Did a total refurb, clean up, including opening the LCD screen to remove dust, new CMOS battery (apple spec), cleaned and re-applied GPU RAM grease/ GPU thermal compound and CPU thermal compound, all of which was super dry, yada yada. Everything looked good, and was buttoning it back up, and GAAAHHHH! I bent the LVDS/LCD connector on the logic board. Ugh.

So a few questions for the old iMac veterans out there:

-Unit won't power on at all now. Shouldn't it at least power on even with a broken LCD connector?
*Perhaps I am wrong, but I was expecting the unit to at least power on for a moment. So I guess something else died? I don't know if it's worth replacing the LCD connector if the entire board died, etc.

-I have another unit or two (from 2010 and 2011) I can swap parts with and troubleshoot some other point of failure. What sort of parts can I swap with this unit from 2010 and 2011 units?


iMac "Core i7" 2.8 27" (Late 2009)2.8 GHz Core i7 (I7-860)



Intro.October 20, 2009Disc.July 27, 2010
OrderMC507LL/AModelA1312 (EMC 2374)
FamilyLate 2009IDiMac11,1
 

Nguyen Duc Hieu

macrumors 68030
Jul 5, 2020
2,734
878
Ho Chi Minh City, Vietnam
A bent LVDS connector should not stop the iMac from booting. Try a close examination on the LVDS socket to see if its pins are abnormal or only the locking mechanism on the sides are bent. I have one iMac 2009 with those broken latches and it's still working well.
Try remove the LCD panel and boot to see if the fans are still spinning.

Basically, iMac 2009 and 2010 are almost the same, so most of the removable parts are swappable: PSU, CPU, RAM, GPU, wifi, isight camera, ODD, SD card readers etc.

The hard part of part swapping,
1> The entire LCD panel + backlight power board of iMac 2009 and 2010 is swappable. You have to swap the backlight power board because of the connectors of the V-sync cable are not compatible, unless you can resolder them.

2> The bare LCD panel (without the T-con board and cables) is swappable among the 3 models. T-con board is the circuitry hidden under black tape on the back of the LCD panel.

3> The PSU is supposed to be swappable among the 3 models.

4> Some of the GPUs (not all) can be used on all 3 models. I didn't test GPUs because I sold all stock GPUs and upgraded to newer ones. Assembling the GPU on iMac 2011 is also troublesome and time-taking, too.

In the worst-case scenario that you can't revive the logic board, the aluminum chassis + LCD panel will make a beautiful 27" 2K monitor, with a proper LCD driver kit (25$ or 75$).
 
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Jimmy-Chivas

macrumors member
Original poster
Aug 22, 2022
31
14
A bent LVDS connector should not stop the iMac from booting. Try a close examination on the LVDS socket to see if its pins are abnormal or only the locking mechanism on the sides are bent. I have one iMac 2009 with those broken latches and it's still working well.
Try remove the LCD panel and boot to see if the fans are still spinning.

Basically, iMac 2009 and 2010 are almost the same, so most of the removable parts are swappable: PSU, CPU, RAM, GPU, wifi, isight camera, ODD, SD card readers etc.

The hard part of part swapping,
1> The entire LCD panel + backlight power board of iMac 2009 and 2010 is swappable. You have to swap the backlight power board because of the connectors of the V-sync cable are not compatible, unless you can resolder them.

2> The bare LCD panel (without the T-con board and cables) is swappable among the 3 models. T-con board is the circuitry hidden under black tape on the back of the LCD panel.

3> The PSU is supposed to be swappable among the 3 models.

4> Some of the GPUs (not all) can be used on all 3 models. I didn't test GPUs because I sold all stock GPUs and upgraded to newer ones. Assembling the GPU on iMac 2011 is also troublesome and time-taking, too.

In the worst-case scenario that you can't revive the logic board, the aluminum chassis + LCD panel will make a beautiful 27" 2K monitor, with a proper LCD driver kit (25$ or 75$).
Thank You very much for your detailed reply Sir!

I will tinker around with it and see what I can find out. It may be time to get the voltmeter out. It appears the LVDS connector is just bent outward away from the logic board a little ways, but is still connected.

I've been seeing 2009/2010 iMac 27" logic boards on Ebay for around $30, so I may go that route if I can find a good deal from a reputable seller.

However, the spare monitor route sounds interesting too. Thanks for the suggestions.
 

Jimmy-Chivas

macrumors member
Original poster
Aug 22, 2022
31
14
A bent LVDS connector should not stop the iMac from booting. Try a close examination on the LVDS socket to see if its pins are abnormal or only the locking mechanism on the sides are bent. I have one iMac 2009 with those broken latches and it's still working well.
Try remove the LCD panel and boot to see if the fans are still spinning.

Basically, iMac 2009 and 2010 are almost the same, so most of the removable parts are swappable: PSU, CPU, RAM, GPU, wifi, isight camera, ODD, SD card readers etc.

The hard part of part swapping,
1> The entire LCD panel + backlight power board of iMac 2009 and 2010 is swappable. You have to swap the backlight power board because of the connectors of the V-sync cable are not compatible, unless you can resolder them.

2> The bare LCD panel (without the T-con board and cables) is swappable among the 3 models. T-con board is the circuitry hidden under black tape on the back of the LCD panel.

3> The PSU is supposed to be swappable among the 3 models.

4> Some of the GPUs (not all) can be used on all 3 models. I didn't test GPUs because I sold all stock GPUs and upgraded to newer ones. Assembling the GPU on iMac 2011 is also troublesome and time-taking, too.

In the worst-case scenario that you can't revive the logic board, the aluminum chassis + LCD panel will make a beautiful 27" 2K monitor, with a proper LCD driver kit (25$ or 75$).
UPDATE: I swapped the PSU (both are 310W) for a known good unit, still won't power on. No fans spinning. I did test the LCD panel that I took apart and cleaned on a good unit and it works fine. Happy about that at least.

So I think the board has died. Do you have a link to this LCD driver kit you mentioned?
 

Nguyen Duc Hieu

macrumors 68030
Jul 5, 2020
2,734
878
Ho Chi Minh City, Vietnam

exploradorgt

macrumors member
Aug 25, 2023
59
31
I will tinker around with it and see what I can find out. It may be time to get the voltmeter out. It appears the LVDS connector is just bent outward away from the logic board a little ways, but is still connected.
I'm late for the party, but for what is worth, I share a few things:

  • I own exactly the same model, and by accident bent the same connectors, but it was a soft case, it was easy to fix with some soldering. The machine is working fine (I'm posting from it right now).
  • Just a technicality: LVDS it's not the cable exactly, this computer uses an eDP LG screen; eDP it's a complete different technology, LVDS is low-voltage differential signaling. So in this case, it's just "the screen cable connector".
  • This computer works perfectly WITHOUT a screen. I have used it via Remote Desktop without the LCD panel completely. I'm posting this because I've found many people around the web wondering.
  • This computer even works perfectly fine WITHOUT A GPU / posting this for the same reason as above.
Suggestions? remove the main board, on the lower left you will find a black tape on top of some leds, these are the diagnostic leds, you can check what turns on to confirm what's happening, you can find information about it on the web. Also, don't underestimate the upper-left ribbon (vsync), check if it's well connected, or if the tracks are fine, this gets easily broken, and in my own experience sometimes the mac works fine without, but it might present glitches, and some times it won't give you any screen signal at all (no backlight), I understand you get no power, but this is worth knowing too.

Good luck.
 
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Jimmy-Chivas

macrumors member
Original poster
Aug 22, 2022
31
14
I'm late for the party, but for what is worth, I share a few things:

  • I own exactly the same model, and by accident bent the same connectors, but it was a soft case, it was easy to fix with some soldering. The machine is working fine (I'm posting from it right now).
  • Just a technicality: LVDS it's not the cable exactly, this computer uses an eDP LG screen; eDP it's a complete different technology, LVDS is low-voltage differential signaling. So in this case, it's just "the screen cable connector".
  • This computer works perfectly WITHOUT a screen. I have used it via Remote Desktop without the LCD panel completely. I'm posting this because I've found many people around the web wondering.
  • This computer even works perfectly fine WITHOUT A GPU / posting this for the same reason as above.
Suggestions? remove the main board, on the lower left you will find a black tape on top of some leds, these are the diagnostic leds, you can check what turns on to confirm what's happening, you can find information about it on the web. Also, don't underestimate the upper-left ribbon (vsync), check if it's well connected, or if the tracks are fine, this gets easily broken, and in my own experience sometimes the mac works fine without, but it might present glitches, and some times it won't give you any screen signal at all (no backlight), I understand you get no power, but this is worth knowing too.

Good luck.
Thanks for the info. Could be useful to convert this unit to a headless server of some sort.
 
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