iMac doesn't wake up after replacing HDD to SSD

Question

iMac Intel 21.5" EMC 2638 & EMC 2742 Late 2013

Model A1418 / Late 2013 / 2.7 & 2.9 GHz Core i5 or 3.1 GHz Core i7 Processor

crwdns2934591:020crwdne2934591:0 crwdns2934593:0crwdne2934593:0 | crwdns2947278:027crwdne2947278:0 crwdns2947270:0crwdne2947270:0

JMPPFR @jmppfr

crwdns2934065:0crwdne2934065:0: 1

2

crwdns2931729:0crwdne2931729:0: Dzi 18, 2020

crwdns2933897:0crwdne2933897:0

iMac doesn't wake up after replacing HDD to SSD

Hi,

I’ve just replaced the HDD of my iMac (21.5” late 2013) with a SSD (and upgrade Memory up to 16GB).

I installed Mac OS Catalina. Everything was fine : the iMac started and run without any problem so I finished to seal the screen.

But, after a while, when I try to wake the iMac, it does not respond. Screen remains black (no backlight).

I have to force the reboot. Then I usually get everything back, but sometimes, even when I restart it, the screen remains black and I have to restart it 2,3 o4 times before it works properly.

I’ve read a lot of thing and my guess is that it comes from the ssd but I have no idea how to fix it…

Thanks for your help !

After having switched back the ssd with the original HDD, I still have the problem... Could it be from the RAM ?

Or from some damages I could have made somewhere ?

Some pictures of the display connectors

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0

crwdns2889612:0crwdne2889612:0 0

crwdns2944067:04crwdne2944067:0

Who's SSD did you install make & model

Did you follow the iFixit guide?

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 Dan crwdne2934271:0

@danj

I installed a Crucial CT500MX500SSD1

I followed the iFxit guide to do the upgrade.

But even after having put back the original HDD, the problem persists...

Thanks !

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 JMPPFR crwdne2934271:0

I was wondering if it could be from the power supply.

On step #36 of this iFisxit guide, I had some trouble to unplug the cable (but I eventually succeed).

iMac Intel 21.5" EMC 2638 RAM Replacement

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 JMPPFR crwdne2934271:0

Generally I recommend doing one task at a time and then checking things to make sure it’s working before doing the next. I would have done the HDD to SSD upgrade first, then prepped it up before tackling the bigger job of upgrading the RAM. That way you know what you need to focus on if something goes wrong (in either case)

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 Dan crwdne2934271:0

crwdns2934285:0crwdne2934285:0

crwdns2933313:01crwdne2933313:0

crwdns2947515:0crwdne2947515:0

crwdns2947517:0crwdne2947517:0

Who's SSD did you install make & model

Did you follow the iFixit guide? — Dan
@danj

I installed a Crucial CT500MX500SSD1

I followed the iFxit guide to do the upgrade.

But even after having put back the original HDD, the problem persists...

Thanks ! — JMPPFR
I was wondering if it could be from the power supply.

On step #36 of this iFisxit guide, I had some trouble to unplug the cable (but I eventually succeed).

iMac Intel 21.5" EMC 2638 RAM Replacement — JMPPFR
Generally I recommend doing one task at a time and then checking things to make sure it’s working before doing the next. I would have done the HDD to SSD upgrade first, then prepped it up before tackling the bigger job of upgrading the RAM. That way you know what you need to focus on if something goes wrong (in either case) — Dan

score 2 · Answer 1 · 2020-04-18T06:31:00-07:00

crwdns2934057:0crwdne2934057:0

Dan @danj

crwdns2934065:0crwdne2934065:0: 490,5crwdns2936485:0crwdne2936485:0

Self employed contract worker

35

338

973

crwdns2931729:0crwdne2931729:0: Dzi 18, 2020

crwdns2933897:0crwdne2933897:0

Lets see what the onboard diagnostic LED’s tell us

Here's a breakdown of the onboard diagnostic LED's:

LED 1 - Indicates that the trickle voltage from the power supply is detected by the main logic board. This LED will remain ON while the iMac is connected to the AC power. The LED will remain on even when the computer has been shut down or put to sleep. The LED will turn off only if the AC power is disconnected or the power supply is faulty.

LED 2 - Indicates that the main logic board has detected proper power from the power supply when the computer is turned on. This LED will be ON when the computer is turned on and the power supply is working correctly.

LED 3 - Indicates that the computer and the video card are communicating. This LED will be ON when the computer is communicating properly with the video card. If LEDs 1 and 2 are ON and you heard the startup sound, but LED 3 is OFF, then the video card might be installed incorrectly or need replacement.

LED 4 - Indicates that the computer and the LCD display panel are communicating. This LED will be ON when the computer is turned on and video signal is being generated. If the LED is ON and there is no image on the LCD display panel, the LCD display panel or inverter might be installed incorrectly or need replacement.

Let us know what you discover

crwdns2934105:0crwdne2934105:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0

crwdns2889612:0crwdne2889612:0 2

crwdns2944067:05crwdne2944067:0:

Thanks a lot for this informations. Here is what I observed :

- When the iMac is asleep : only LED 1 is on

- By luck, for the first time, it awoke when a press a key => All LED's were on. But, the screen started having short blacks out for half a second (when it happened, only LED 4 blank out). It lasted for a few minutes, like if there were a short-circuit.

- Eventually, I put the iMac to sleep, wait a few minutes, then try to woke it. I could hear the error sound when I press cmd + q for example (so it is awaken) but the screen remained black => Just LED 1,2 and 3 were on. LED 4 is off.

Once again, thanks a lot for this technical advanced help !

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 JMPPFR crwdne2934271:0

Take a picture of the display cables end and the logic board connector. I fear you damaged one or both Adding images to an existing question

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 Dan crwdne2934271:0

@danj : done. Pictures are uploaded.

Strangely, after manipulating the display in order to check the LED and to take the pictures, it seems to be ok when I try to wake the iMac. But I had to try 3 times to boot it because the display wouldn't light on.

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 JMPPFR crwdne2934271:0

I don't see any damage in the connectors is there any damage within the cable.

crwdns2934271:0Dzi 18, 2020crwdnd2934271:0 Dan crwdne2934271:0

Eventually, after manipulating the display, unplugging et plugging the cables, it seems to work... Sometimes, there are some strange blinks (black, or some "phantom image" that appears during a fraction of second).

Could it be a bad contact on some wires or on the logic board ?Is there any way to check that ?

Thanks a lot for your help

crwdns2934271:0Dzi 19, 2020crwdnd2934271:0 JMPPFR crwdne2934271:0

crwdns2934285:0crwdne2934285:0