Perfect !! I have tried everything , watched soo many UA-cam videos but nothing worked. I bit the bullet and soldered on the wire. It works perfectly ! Thank you soo much for a fantastic video 😊👍
Very well made Video, Thank you for such clear and good instructions. I have the same Machine, but my Backlight is only partially off, often flickering at start, sometimes going dark altogether. I already bought a new, tested Inverter and changed it, but that lead to no changes in behavior. On the "on/Off" trigger pin you point out in the Video, I get a voltage of roughly 1,5 V (fluctuating between 1.58 and 1.44 V) - I'm not sure if that is what is causing the issue, as the Voltage you took from the LED only is 1.8V, and your display works... May I ask where you got the Info what Voltage should be present on that pin? On my search for clues on the Web I came about different statements what that specific Voltage should be (1.5V, 3.3V, 5V..) . To know a definitive answer could help me find the root of my problem. Otherwise I simply would take 3.3V from the SATA-Power Connector and see what happens. :D Again thank you for your Video, on this otherwise rarely in-depth talked about issue with old imacs. :)
From memory I found that it is supposed to be 3.3v from a schematic. I would suggest cutting the wire and adding an extension wire as I have in the video. Then either solder to the 1.8v from led 4 as I did or solder to the 3.3v of led 3, on the other side of its resistor.
Hi there, I have an A1225 , powers on I can hear chime but black screen . LED1 is on V = 1.8 LED2 is on V= 1.8 LED3 is off V=3.3 LED 4 is off V= 0 Terminal 3 on connector is 0V , I do not you schematic diagram to trace circuit . Any help appriciated
Hi gud day sir...is it possible for imac 20".i'd try but the bong sound was lost maybe in 20" 2009 is a different circuitry...do you have any idea of this...tnx a lot
So my old max is turn in but it goes black, i click on the mouse and it remains in the black screen but i see the mouse. I quickly see a pop up but can't make out what it is because it goes blk. Any suggestions
My imac 27 2011 screen goes complete black while imac is still working ( Screen sharing to macbook still working too) .. when I press power button for 1s and click on the mouse screen came back on (sometimes i need to repeat it few times) ,,, I've done PRam and nvram reset ,imac was cleaned Gpu ,Pcu termal paste change but did not helped ... Any advice ? ( Screen sharing to macbook still working during black screen on imac ) .. Any advice ?
I don't sorry, I would suggest testing that the inverter is getting power (not just the trigger signal). Off the top of my head the diagnostic process I would follow would be... 1. Power to inverter, 2. Inverter output (high voltage) 3. Backlight. Sorry I can't be of more help. Good luck.
@@rschunkster well i just found THIS! seems to good to be true but he did exactly what I did before the no display happened to him: www.ifixit.com/Answers/View/190777/iMac+won%27t+start+after+HDD+replacement+-+no+chime,+black+screen,+DVD
@@rschunkster by the way an external monitor didnt work for me, so it could be in fact your inverter, check this out: ua-cam.com/video/qD0GQz3fIeo/v-deo.html
Can I do this same repair on a different age imac? I found led4. My setup looks a little different then yours. I see Led 1, Led2, Led4, then it shows four circles 1, 2, 3, 4, at the fourth circle it shows led3. And the 3rd circle it had a rectangle near it that does not look like the two rectangles above and the one below it. It looks like it has a small hole in it. It looks silver, instead of yellow like the other 3 rectangles that are near 1,2,3,4 circles. I wish I could show you a screenshot, would make it easier to explain.
In theory if the iMac has the exact same issue than the fix should work. LED 4 comes on when the screen should be on so using it is still a good option. U should be able to solder onto the side of the LED. However being a different machine it may not be the same cable that this needs to connect to.
Ok, I hope you still remember this issue. I have a similar problem on my sisters 8,1 20 inch iMac, it has only one light bulb (the bottom one) working at all times, and the upper part of the screen turns on for just a brief second, after waking a mac from sleep, and then the upper backlight of the screen turns off.
@@AronBezzina Yes, that's right, half of the screens backlight doesn't work. I don't know the exact details of what backlight system there is used underneath the display, but we'd like to get it fixed, - I've had experience from simple repairs, might be able to do soldering if necessary. Thanks for looking into it!
@@robiocrafteuro I think the backlight will possibly be a string (or 2) of LEDs if one dies the whole string may be dead, you may be able to replace the dead LED but it's going to be easier to get a replacement screen, seeing the age of the Mac you may be able to find a dead one cheap online that you can get a replacement screen from. Good luck :)
Great video! I hope you still reply to comments after two years... I came to this page by google search because my 2008 iMac 24" has black screen issue. When powered on, I do get the apple chime sound, and I see the fans are running but nothing on the screen. I tried shining a flashlight into the screen, still see nothing. Then I did the voltage test as shown in your video, it came out as zero. One thing I noticed is that in your video, all of 4 LEDs are on with green light. But I only got LED 1 and 2 on, not 3 and 4. I suspect that my graphics card is dead, but not sure. I cannot find the right cable (mini DVI ?) to connect it to an external monitor to verify. Any suggestion or tip? Thanks!
If you have an integrated graphics card u won’t get led 3. If you have an actual graphics card then no led 3 means it’s not working. U can try take the card out and try the oven trick but that’s not a great fix, it will be temporary at best. Buying a replacement card wouldn’t be worth it. If u have no graphics card (intel graphics) (not even sure if this was an option with ur model) then u won’t get led 3 and you probably have an issue different from this video.
@@AronBezzina Wow, thanks for the quick response. Really appreciate it. I do have a discrete graphics card and your reply somehow confirmed my suspicion. I will see if I can get a spare part for it.
@@AronBezzina Hi Aron, just to follow up on this. It turns out that it is the graphics card and 2008 iMac does have discrete graphics card. So, I replaced it and now it works perfectly. Thanks again for you help.
Any idea if the same issue occurs on the 2010 27" models? On mine, the screen lights up briefly before going black. The LCD is working when viewed under a bright light. Changing the driver board hasn't helped, though I can't guarantee that the "new" one worked any better to begin with.
Peter Charlton I think that model had graphics chips die so that’s probably your problem, you may still have the on signal as an issue tho, so I suggest looking for the voltages as shown in the video, you may need to find a schematic for your model to workout where the backlight on trigger is .
@@LongPeter Hi Peter, Not sure if you've got the issue resolved in the meanwhile but you can also check your ambient light sensor. I've had this problem with a 2010 27" where the ambient light sensor was broken, which the brightness is usually based on. Because of this, the screen stayed black forever.
@@jaspercardol Thanks Jasper, that's an interesting idea. I wouldn't have thought the ambient light sensor could dim the backlight all the way to black.
Excellent video. Super easy to follow though the idea of replicating work makes me cringe. 2007 24” iMac: I don’t think I can see an image with the flash light. I hear the boot chime. I try login and hear the hard drive spin but no image. Any ideas? (I’m going to crack open iMac because I at least need to get hard drive out and copy data)
CSB5K try the external video port if you have an adapter. I think however the issue is likely a dead graphics chip making the machine not really something worth repairing. That being said if it is a dead chip and you are going to toss it out you may as well try heating the graphics chip with a heat gun. It won’t permanently fix anything but it may keep the machine running for a bit longer.
Excellent video. My A1224 Imac has the same problem, but I can't find the exactly point below the fourth LED to solder the wire. I connected the wire bellow the third LED, the screen works, but the fans starts to very fast. I took a picture of the diagnostic LED area, if there is any way for you to see the photo, maybe you could help me. Thanks a lot.
Fernando I don’t think u can attach a pic in UA-cam. Find me on Facebook ( Aron Bezzina. ). Does ur 4th led light up ? The fan usually spins fast if a sensor is not plugged in such as the temp sensor for the HDD, DVD or LCD. Double check they connected :)
Hi Aron, my friend gave me an iMac 2011 21.5" and I am new to Mac. I tried to add a SSD, clean the fan and changing thermal paste for both GPU and CPU. After I assemble them back together. I got blackscreen. All 4 LEDs are on but just no image. There was once image flashing but I cannot repeat this. I was thinking my thermal compound is a bad one so I have a new one on order. Do you have any suggestion? Thanks a lot.
I can't quite figure out what's wrong with mine. The iMac [early 2008] restarts several times before being stable. Of late it shuts down more often than before [3 months problem]. 1. I noticed that the first 3 LED lights work just fine but they quickly go off [except #LED 1] whenever #LED4 comes on. This happens several times until it finally stabilizes and turns on [at this point, all the 4 LED lights are on and performing normally]. 2. I further examined the inverter area and discovered that one of the 4 connectors [from the inverter to the screen] was burnt [the plastic was melted]. I replaced it with a good one hoping that the problem will be solved but it persisted. How can I solve this? Thank you
Stop Code Zero Echo that could be done, however doing so would mean the backlight is on whenever the computer is on, even when the screen is supposed to be off. The place I got the power from was selected specifically as it only ever has power when the screen is supposed to be on (ie off if the screen is sleeping)
@@AronBezzina I have a 2007 imac 20in with what appears to be a bad inverter. (I can see the apple logo and login screen if I shine a flashlight at the screen and it sends a pic to an ext monitor) is this model affected by a gpu bug you described? I plan to look further into it come payday as I need a T8 torx and suction cups to get in to test with my meter.
Stop Code Zero Echo I am not sure if your model has the same problem or not. What you should do is check with a multimeter if the “on signal” is being produced and sent to the inverter. If it is then this is not going to help you, it may be a blown backlight. Good luck :)
Just whatever is at hand should be fine. Wire from a USB cable, an old mouse, some Ethernet cable. It won’t really matter. It just has to be thin enough to solder to the LED so nothing thick like power cable.
As in, you can plug-in an external screen and it works fine, but the main screen isn’t coming on, and it’s not just a backlight issue, there is no image at all? It could be a lot of things. Check the software settings, Check the diagnostic LEDs see what they say
@@AronBezzina I think it maybe be my video cable because it’s lose where it connects to the screen... but should the backlight at least be on or does it not turn on when that isn’t connected
@@GeoMetro2 I am not sure if the computer may notice there is no screen connected and as a result not light up the backlight. I would suggest fixing the bad connection. also, u can use the diagnostic LEDs to see what part isn't working look at time stamp 5:05 for info on the LEDs (pause and read the screen)
Led 4 not being on means the computer is not talking to the screen. This would mean that you wouldn’t have the image on the screen with no backlight, you would have no image at all. You may have a bad LVDS cable (the cable from the screen to the computer) or a bad connector, or bad screen.
Chris Nova777 if the backlight works but isn’t bright enough it could be a few things: -The backlight could be failing (part of the LCD screen) -the signal to the inverter board that tells it what brightness to be may not be changing -the inverter board may have an issue
@@AronBezzina when i first got the iMac i remember it was very white + bright, but over time its become nowhere near as white and dull, and yes the brightness controls don't seem to be working properly.. the screen changes slightly in brightness but doesn't seem to have the proper functionality as the brightness controls do on my MBP laptop.
Perfect !! I have tried everything , watched soo many UA-cam videos but nothing worked.
I bit the bullet and soldered on the wire. It works perfectly ! Thank you soo much for a fantastic video 😊👍
Excellent, got my iMac 2008 24 running again. Important to use some flux before soldering the SMD led contact.
This is so well made. I don't have a mac but I still watched the whole thing, was so easy to watch!
Very well made Video, Thank you for such clear and good instructions.
I have the same Machine, but my Backlight is only partially off, often flickering at start, sometimes going dark altogether. I already bought a new, tested Inverter and changed it, but that lead to no changes in behavior. On the "on/Off" trigger pin you point out in the Video, I get a voltage of roughly 1,5 V (fluctuating between 1.58 and 1.44 V) - I'm not sure if that is what is causing the issue, as the Voltage you took from the LED only is 1.8V, and your display works... May I ask where you got the Info what Voltage should be present on that pin? On my search for clues on the Web I came about different statements what that specific Voltage should be (1.5V, 3.3V, 5V..) . To know a definitive answer could help me find the root of my problem.
Otherwise I simply would take 3.3V from the SATA-Power Connector and see what happens. :D
Again thank you for your Video, on this otherwise rarely in-depth talked about issue with old imacs. :)
From memory I found that it is supposed to be 3.3v from a schematic. I would suggest cutting the wire and adding an extension wire as I have in the video. Then either solder to the 1.8v from led 4 as I did or solder to the 3.3v of led 3, on the other side of its resistor.
Hi there, I have an A1225 , powers on I can hear chime but black screen . LED1 is on V = 1.8 LED2 is on V= 1.8 LED3 is off V=3.3 LED 4 is off V= 0
Terminal 3 on connector is 0V , I do not you schematic diagram to trace circuit . Any help appriciated
Hi gud day sir...is it possible for imac 20".i'd try but the bong sound was lost maybe in 20" 2009 is a different circuitry...do you have any idea of this...tnx a lot
Darnit i need a workspace to try this im literally trying to fix my computer on my bed 😂
So my old max is turn in but it goes black, i click on the mouse and it remains in the black screen but i see the mouse. I quickly see a pop up but can't make out what it is because it goes blk. Any suggestions
My imac 27 2011 screen goes complete black while imac is still working ( Screen sharing to macbook still working too) .. when I press power button for 1s and click on the mouse screen came back on (sometimes i need to repeat it few times) ,,, I've done PRam and nvram reset ,imac was cleaned Gpu ,Pcu termal paste change but did not helped ... Any advice ? ( Screen sharing to macbook still working during black screen on imac ) .. Any advice ?
I have an iMac 2008 20" and the backlight isn't coming on. I do however have the 3v at the connector, do you have a video on the other type of issue?
I don't sorry, I would suggest testing that the inverter is getting power (not just the trigger signal). Off the top of my head the diagnostic process I would follow would be... 1. Power to inverter, 2. Inverter output (high voltage) 3. Backlight. Sorry I can't be of more help. Good luck.
did you find the issue?
@@AVSCDvideoproduction No i've been using an external monitor since, may have a look now we all have a lot more time!
@@rschunkster well i just found THIS! seems to good to be true but he did exactly what I did before the no display happened to him: www.ifixit.com/Answers/View/190777/iMac+won%27t+start+after+HDD+replacement+-+no+chime,+black+screen,+DVD
@@rschunkster by the way an external monitor didnt work for me, so it could be in fact your inverter, check this out: ua-cam.com/video/qD0GQz3fIeo/v-deo.html
Can I do this same repair on a different age imac? I found led4. My setup looks a little different then yours.
I see Led 1, Led2, Led4, then it shows four circles 1, 2, 3, 4, at the fourth circle it shows led3. And the 3rd circle it had a rectangle near it that does not look like the two rectangles above and the one below it. It looks like it has a small hole in it. It looks silver, instead of yellow like the other 3 rectangles that are near 1,2,3,4 circles. I wish I could show you a screenshot, would make it easier to explain.
In theory if the iMac has the exact same issue than the fix should work. LED 4 comes on when the screen should be on so using it is still a good option. U should be able to solder onto the side of the LED.
However being a different machine it may not be the same cable that this needs to connect to.
@@AronBezzina Thank you, I will try this soon and let you know if it worked
@@jamer379 did it work ?
Ok, I hope you still remember this issue. I have a similar problem on my sisters 8,1 20 inch iMac, it has only one light bulb (the bottom one) working at all times, and the upper part of the screen turns on for just a brief second, after waking a mac from sleep, and then the upper backlight of the screen turns off.
are you saying that only half of the backlight works? if so then you may have a dead backlight.
@@AronBezzina Yes, that's right, half of the screens backlight doesn't work. I don't know the exact details of what backlight system there is used underneath the display, but we'd like to get it fixed, - I've had experience from simple repairs, might be able to do soldering if necessary. Thanks for looking into it!
@@robiocrafteuro I think the backlight will possibly be a string (or 2) of LEDs if one dies the whole string may be dead, you may be able to replace the dead LED but it's going to be easier to get a replacement screen, seeing the age of the Mac you may be able to find a dead one cheap online that you can get a replacement screen from. Good luck :)
How many volts trows the black cable you cut to the four light?
Great video! I hope you still reply to comments after two years... I came to this page by google search because my 2008 iMac 24" has black screen issue. When powered on, I do get the apple chime sound, and I see the fans are running but nothing on the screen. I tried shining a flashlight into the screen, still see nothing. Then I did the voltage test as shown in your video, it came out as zero. One thing I noticed is that in your video, all of 4 LEDs are on with green light. But I only got LED 1 and 2 on, not 3 and 4. I suspect that my graphics card is dead, but not sure. I cannot find the right cable (mini DVI ?) to connect it to an external monitor to verify. Any suggestion or tip? Thanks!
If you have an integrated graphics card u won’t get led 3. If you have an actual graphics card then no led 3 means it’s not working. U can try take the card out and try the oven trick but that’s not a great fix, it will be temporary at best. Buying a replacement card wouldn’t be worth it.
If u have no graphics card (intel graphics) (not even sure if this was an option with ur model) then u won’t get led 3 and you probably have an issue different from this video.
@@AronBezzina Wow, thanks for the quick response. Really appreciate it. I do have a discrete graphics card and your reply somehow confirmed my suspicion. I will see if I can get a spare part for it.
@@AronBezzina Hi Aron, just to follow up on this. It turns out that it is the graphics card and 2008 iMac does have discrete graphics card. So, I replaced it and now it works perfectly. Thanks again for you help.
Any idea if the same issue occurs on the 2010 27" models? On mine, the screen lights up briefly before going black. The LCD is working when viewed under a bright light. Changing the driver board hasn't helped, though I can't guarantee that the "new" one worked any better to begin with.
Peter Charlton I think that model had graphics chips die so that’s probably your problem, you may still have the on signal as an issue tho, so I suggest looking for the voltages as shown in the video, you may need to find a schematic for your model to workout where the backlight on trigger is .
@@AronBezzina Thanks, I'll check it out. It still runs an external monitor just fine, FYI.
@@LongPeter Hi Peter,
Not sure if you've got the issue resolved in the meanwhile but you can also check your ambient light sensor. I've had this problem with a 2010 27" where the ambient light sensor was broken, which the brightness is usually based on. Because of this, the screen stayed black forever.
@@jaspercardol Thanks Jasper, that's an interesting idea. I wouldn't have thought the ambient light sensor could dim the backlight all the way to black.
Nice one. Worked like a charm. Thanks!
StarSixTNine I’m happy the video helped :)
Excellent video. Super easy to follow though the idea of replicating work makes me cringe.
2007 24” iMac: I don’t think I can see an image with the flash light. I hear the boot chime. I try login and hear the hard drive spin but no image. Any ideas?
(I’m going to crack open iMac because I at least need to get hard drive out and copy data)
CSB5K try the external video port if you have an adapter. I think however the issue is likely a dead graphics chip making the machine not really something worth repairing. That being said if it is a dead chip and you are going to toss it out you may as well try heating the graphics chip with a heat gun. It won’t permanently fix anything but it may keep the machine running for a bit longer.
Excellent video.
My A1224 Imac has the same problem, but I can't find the exactly point below the fourth LED to solder the wire.
I connected the wire bellow the third LED, the screen works, but the fans starts to very fast.
I took a picture of the diagnostic LED area, if there is any way for you to see the photo, maybe you could help me.
Thanks a lot.
Fernando I don’t think u can attach a pic in UA-cam. Find me on Facebook ( Aron Bezzina. ). Does ur 4th led light up ?
The fan usually spins fast if a sensor is not plugged in such as the temp sensor for the HDD, DVD or LCD. Double check they connected :)
Aron, thanks for answering.
The 4th led lights up.
I’ll try to send you a pic, so you can help me.
👍
Excellent mate Thank you very much .. work perfect
JA Computer & Mobile phone Repair really happy to hear that mate :)
Hi Aron, my friend gave me an iMac 2011 21.5" and I am new to Mac. I tried to add a SSD, clean the fan and changing thermal paste for both GPU and CPU. After I assemble them back together. I got blackscreen. All 4 LEDs are on but just no image. There was once image flashing but I cannot repeat this.
I was thinking my thermal compound is a bad one so I have a new one on order.
Do you have any suggestion? Thanks a lot.
Check the ram, also double check the display, make sure it’s plugged in on all connections. Also try test with external monitor.
Aron Bezzina thanks a lot for your suggestion. I will try when my new thermal paste arrive
I can't quite figure out what's wrong with mine. The iMac [early 2008] restarts several times before being stable. Of late it shuts down more often than before [3 months problem].
1. I noticed that the first 3 LED lights work just fine but they quickly go off [except #LED 1] whenever #LED4 comes on. This happens several times until it finally stabilizes and turns on [at this point, all the 4 LED lights are on and performing normally].
2. I further examined the inverter area and discovered that one of the 4 connectors [from the inverter to the screen] was burnt [the plastic was melted]. I replaced it with a good one hoping that the problem will be solved but it persisted.
How can I solve this? Thank you
It could be a bad power supply. I would suggest using a multimeter to check the voltages coming out of the psu.
@@AronBezzina I’ll do that, thanks. Does using a UPS make a difference? Coz I’m using one
@@isaacmathewajuoga8026 as long as it's working fine then no (outputting 240v or 110v)
@@AronBezzina just checked. Its output is 230V
Could you not just run a jumper wire from the imac's PSU 3.3v power rail to the the inverter on/off signal wire?
Stop Code Zero Echo that could be done, however doing so would mean the backlight is on whenever the computer is on, even when the screen is supposed to be off. The place I got the power from was selected specifically as it only ever has power when the screen is supposed to be on (ie off if the screen is sleeping)
@@AronBezzina I have a 2007 imac 20in with what appears to be a bad inverter. (I can see the apple logo and login screen if I shine a flashlight at the screen and it sends a pic to an ext monitor) is this model affected by a gpu bug you described? I plan to look further into it come payday as I need a T8 torx and suction cups to get in to test with my meter.
Stop Code Zero Echo I am not sure if your model has the same problem or not. What you should do is check with a multimeter if the “on signal” is being produced and sent to the inverter. If it is then this is not going to help you, it may be a blown backlight.
Good luck :)
Sometimes i can get it to work with cmd+alt+p+r, but sometimes it doesn't work at all...
what cable can i use to connect them together? does it have to be a Ribbon cable?
Just whatever is at hand should be fine. Wire from a USB cable, an old mouse, some Ethernet cable. It won’t really matter. It just has to be thin enough to solder to the LED so nothing thick like power cable.
What if there is no image or backlots but the computer is functioning as supposed to... ?
As in, you can plug-in an external screen and it works fine, but the main screen isn’t coming on, and it’s not just a backlight issue, there is no image at all?
It could be a lot of things.
Check the software settings,
Check the diagnostic LEDs see what they say
@@AronBezzina I think it maybe be my video cable because it’s lose where it connects to the screen... but should the backlight at least be on or does it not turn on when that isn’t connected
@@GeoMetro2 I am not sure if the computer may notice there is no screen connected and as a result not light up the backlight. I would suggest fixing the bad connection. also, u can use the diagnostic LEDs to see what part isn't working look at time stamp 5:05 for info on the LEDs (pause and read the screen)
@@AronBezzina so I got backlight mow that I messed with the gpu being seated correctly and I still don’t have video...
@@GeoMetro2 do u get external video? What LEDs light up
Hi, is it possible to use that imac model as a monitor for my macbook air? Thx 4 help
Kirsten Wassermann I don’t think you can with that model however I have never tried. For more info pls look here :)
support.apple.com/en-au/HT204592
Will this work on a 2011?imac 27 inch ?
Maybe, but only if that is the actual issue.
Very Good my bro
Would you be able to fix my monitor? I will pay you for your head work of course!
It’s the same one
@@typicalvictor877 Are you saying you have the same issue on the same model iMac?
What is your location?
Aron Bezzina I live in union city Ca
Aron Bezzina my Imac doesn’t turn on
Aron Bezzina power seems to be going through
My LED 4 is not on at all tho
Led 4 not being on means the computer is not talking to the screen. This would mean that you wouldn’t have the image on the screen with no backlight, you would have no image at all. You may have a bad LVDS cable (the cable from the screen to the computer) or a bad connector, or bad screen.
what about if the backlight isnt as bright as it is suposed to be? is that fixed by replacing the inverter board? or the entire screen?
Chris Nova777 if the backlight works but isn’t bright enough it could be a few things:
-The backlight could be failing (part of the LCD screen)
-the signal to the inverter board that tells it what brightness to be may not be changing
-the inverter board may have an issue
@@AronBezzina when i first got the iMac i remember it was very white + bright, but over time its become nowhere near as white and dull, and yes the brightness controls don't seem to be working properly.. the screen changes slightly in brightness but doesn't seem to have the proper functionality as the brightness controls do on my MBP laptop.
Chris Nova777 my guess is it’s probably the backlight, this basically requires a new screen
Great Video thx I had the same problem and did what Bezzina did, only the third led was soldered with fast glue ahahaha and it worked perfectly
IM FROM INDONESIA, THANK YOU BROOO