When Your IMac Won’t Turn On, What Should You Do?
We will thoroughly explore your repair options and associated costs if your iMac is experiencing a severe hardware problem
If your iMac won’t turn on, there are a number of possible causes. In order to fix it, you will need to figure out how unresponsive your iMac is. If it doesn’t work at all, you may be able to fix it easily. Logic board issues may be more complex in slightly responsive iMacs with fan spin noise.
Ensure that your iMac is receiving power
Firstly, make sure the power cable is intact and firmly connected to both your iMac and an electrical outlet. This is a crucial step, but is relatively straightforward. You can test an outlet’s functionality with a lamp or a mobile phone charger if you’re unsure.
To test your iMac power cord, use a standard PC power cord. They are identical.
Check the power button for a stuck position
Sticky power buttons or faulty power buttons will not be able to send a valid control signal to the logic board, so your iMac will not turn on.There is often dirt accumulating inside the power button, which causes it to stick. It takes a long time, even for skilled Mac repair technicians, to replace the power button on an iMac. To access the power button, remove the screen, power supply, and logic board first. By following these steps, you can resolve this issue without replacing the button:
- The first step is to unplug your iMac’s power cord.
- The iMac should be placed on a flat desktop with the screen facing down.
- To lubricate the button, apply one or two drops of WD-40 lubricant. Let the liquid sink into the button.
- Let the lubricant soften the dirt for a few minutes.
The iMac power button operates at 3.3V DC, which is a very safe voltage for humans. Furthermore, WD-40 is an electrically safe lubricant.
Keep pushing and releasing the button to get the dirt out.
Clean the dirt with a tissue.
If any external devices are faulty, check them
The Mac will not turn on if it detects an accessory connected to it has short circuits or draws a large amount of current. This is a safety measure.
It could be one of your peripherals causing your iMac repair ptoblem not to turn on. Unplug all the cables attached to your iMac, including the printer cable, network cable, firewire cable, USB hub, external USB hard drive, and mini display cable.
The SMC or T2 chip should be reset
Your iMac’s System Management Controller (SMC) receives power button signals and initiates and supervises the entire power-on process. You can think of the SMC as a small computer running a miniature operating system, which may encounter software issues on rare occasions. You may need to perform an SMC reset to resolve such an issue if your iMac experiences it.
With the arrival of the Apple Silicon CPU M1 or M2 in 2020, the SMC functionality will also be integrated into these newer processors, too. Apple integrated the SMC chip into the Apple T2 Security chip beginning in 2018.
Remove power cable and Reconnect the power cable after 15 seconds.
When your iMac turns on, wait for 5 seconds, then press the power button.
Since Mac Mini and Mac Pro computers have a single power source (main power), this method can be used. It is difficult to disconnect the internal battery on a Mac laptop because it has two power sources (charger and battery).
Run a power cycle
Performing a power cycle forces the iMac to return to its off state.
The iMac will not respond to normal wake-up signals, such as pressing the keyboard keys or clicking the mouse button, if it gets stuck in the Sleep state. Perform a power cycle to bring the iMac back to the off state. The Mac should now return to the off state after you unplug the power cable and wait 15 seconds before plugging it back in. Now try turning it on again by pressing the power button again.
Look for signs of power
Are you noticing air flow from the fan vent holes on the back of your iMac? Can you hear the fan spinning, along with the hard disk and Super Drive motor? These signs suggest that your iMac is powered on, but there may be additional issues hindering its functionality. Check for any lights in a dark room; if nothing appears on the screen, try shining a flashlight at the top right corner. Increase screen brightness by pressing the up button if dim text is visible.
Using a mini display port or thunderbolt port, connect an external monitor to your iMac. If the external monitor displays anything, your screen is definitely faulty.
Check if the RAM is faulty
Your iMac may not turn on if you hear repeated beeps. RAM faults could be causing the problem.
Whenever you hear one beep, it means your iMac repair problem is due to not detecting any RAM. If you recently replaced or upgraded the memory, check to make sure it was installed correctly.
Your iMac RAM is badif you get three consecutive beeps followed by a five-second pause.
The firmware of the T2 security chip can be restored if it has been corrupted
The SMC chip has been replaced by the Apple T2 security chip in the new Macs. The T2 chip takes over the role of the SMC chip, so the iMac won’t power up if the T2 chip is not functioning.
You may have bricked your iMac if you updated your macOS to one that contains a device firmware update (DFU) but failed to complete it all.A bricked iMac needs a working host MacBook, the firmware from Apple’s website, and a USB-C cable to transfer the firmware to the bricked iMac.
Make sure your host MacBook is connected to the internet before you download Apple Configurator 2. You may need to update to the latest macOS to run the app.
- Unplug your bricked iMac’s power cord.
- Connect one end of the USB-C cable to any port on your host MacBook.
Your bricked iMac’s master port is the USB-C port next to the Ethernet port. Connect the other end of the USB-C cable to the master port.While holding the power button, plug in your iMac’s power cord. Hold the power button for about 3-5 seconds until you see the DFU logo on the host MacBook.
The bricked iMac is now in DFU mode.
Once you’ve selected the DFU device on the screen, select Action from the menu bar. On the pull-down menu bar, select Advance and select Revive Device.
Check for faulty iMac power supply
iMac power supply failures account for the majority of dead iMacs. If you have gone through all the checks discussed above and your iMac still doesn’t turn on, you most likely have a failed power supply, especially if your iMac won’t turn on after power outage.
Follow this procedure to check the iMac power supply:
- Remove the power cable from the main powerpoint.
- Wait for at least 10 minutesuntil the big capacitors in the power supply have been completely discharged (from 395V to 0V).
- Remove the iMac screen from its aluminium frame.
- Plugin the power cable back to the main powerpoint.
- Check for the four LED lights on the logic board. If no LED light is on, you have a faulty iMac power supply.
Check the logic board of the iMac for faulty components
Every model of iMac has four diagnostic LED lights. The location of the LEDs varies from model to model. Their behavior tells you a lot about the machine.
The S5 led indicates that the logic board has received power from the power supply and is currently in standby mode (technical term S5 state).
All_SYS_PWRGD Led. This imeans “all system powers are good”. When all system powers are good, including CPU and RAM, but not GPU, this light will be illuminated.
The GPU GOOD LED will illuminate if the GPU has been powered and has passed the self-checking test.
VIDEO ON led. When the GPU detects an iMac screen connected to the logic board, it will turn on the backlight of the screen and the VIDEO ON led.
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