crwdns2933423:0crwdne2933423:0
crwdns2918538:0crwdne2918538:0

crwdns2934243:0crwdne2934243:0 Michael Epstein

crwdns2947189:0crwdne2947189:0:

iMac not starting after upgrading CPU and pci-e storage

crwdns2934249:0crwdne2934249:0:

Hi,
I attempted to upgrade my 2019 5k 27” imac by changing the CPU and the pci-e storage, and replacing the sata disk with more storage. I bought components and tools from OWC and a new i9 9900K CPU.
I followed the official OWC guide for getting into the imac, which seemed to work quite well, but when I put the components back together and before reattaching the screen I tried to start the imac to be satisfied everything was in order.
I pressed the power button. The fan starts, but there is no POST (or bong noise) and the display is just black.
I’ve looked at the LED diagnostic lights
[image|2404807]
and it looks to my knowledge that LED 2,3 are lit when I power up the imac, LED 2 is lit when the AC is connected. But not LED 1 at any point, or 4 or 5 when the display is connected.
Does anyone know what to try at this point? I have tried reseating the CPU but get the same result. The other things I will try are:
# reseat the RAM (haven’t changed this component thought, and worked fine before)
# put the old components back
+
Any other suggestions gratefully received before I sent for repair before inevitably deciding it is too expensive to repair economically.
=== Update (05/16/2021) ===
+
Hi Dan, I don't think so though I've had to add and remove the screen to test it
[image|2404899]
[image|2404912]
[image|2404901]
I'll have a read through your link, thanks again.
=== Update (05/20/2021) ===
+
To answer this question - the solution which worked for the '''initial''' question was to reseat the RAM. The five LEDs then lit up as expected and the computer worked as upgraded.
I damaged the display power cable completing the reassembly of the iMac - the LED shows the Apple logo on startup but there is no backlight. I can’t determine whether the logic board has been damaged (probably given that the 5th LED is permanently lit as per @danj’s comment), or whether the cable is fried, and I need a new screen. I’m not sure it is worth paying to find out at this point when I have an external monitor which works for sure.
I hope this helps future ifixiters.

crwdns2866306:0crwdne2866306:0:

iMac Intel 27" Retina 5K Display 2019

crwdns2915684:0crwdne2915684:0:

open

crwdns2934251:0crwdne2934251:0:

+701047

crwdns2934245:0crwdne2934245:0 Dan

crwdns2947189:0crwdne2947189:0:

iMac not starting after upgrading CPU and pci-e storage

crwdns2934249:0crwdne2934249:0:

Hi,
I attempted to upgrade my 2019 5k 27” imac by changing the CPU and the pci-e storage, and replacing the sata disk with more storage. I bought components and tools from OWC and a new i9 9900K CPU.
I followed the official OWC guide for getting into the imac, which seemed to work quite well, but when I put the components back together and before reattaching the screen I tried to start the imac to be satisfied everything was in order.
I pressed the power button. The fan starts, but there is no POST (or bong noise) and the display is just black.
I’ve looked at the LED diagnostic lights
[image|2404807]
and it looks to my knowledge that LED 2,3 are lit when I power up the imac, LED 2 is lit when the AC is connected. But not LED 1 at any point, or 4 or 5 when the display is connected.
Does anyone know what to try at this point? I have tried reseating the CPU but get the same result. The other things I will try are:
# reseat the RAM (haven’t changed this component thought, and worked fine before)
# put the old components back
-
Any other suggestions gratefully received before I sent for repair before inevitably deciding it is too expensive to repair economically.
+=== Update (05/16/2021) ===
+Hi Dan, I don't think so though I've had to add and remove the screen to test it
+
+[image|2404899]
+
+[image|2404912]
+
+[image|2404901]
+
+I'll have a read through your link, thanks again.
+
=== Update (05/20/2021) ===
-
To answer this question - the solution which worked for the '''initial''' question was to reseat the RAM. The five LEDs then lit up as expected and the computer worked as upgraded.
-I damaged the display power cable completing the reassembly of the imac - the LED shows the Apple logo on startup but there is no backlight. I can’t determine whether the logic board has been damaged (probably given that the 5th LED is permanently lit as per @danj’s comment), or whether the cable is fried, and I need a new screen. I’m not sure it is worth paying to find out at this point when I have an external monitor which works for sure.
+I damaged the display power cable completing the reassembly of the iMac - the LED shows the Apple logo on startup but there is no backlight. I can’t determine whether the logic board has been damaged (probably given that the 5th LED is permanently lit as per @danj’s comment), or whether the cable is fried, and I need a new screen. I’m not sure it is worth paying to find out at this point when I have an external monitor which works for sure.
I hope this helps future ifixiters.
-
-=== Update (05/16/2021) ===
-
-Hi Dan, I don't think so though I've had to add and remove the screen to test it[image|2404899] [image|2404912][image|2404901].
-
-I'll have a read through your link, thanks again.

crwdns2866306:0crwdne2866306:0:

iMac Intel 27" Retina 5K Display 2019

crwdns2915684:0crwdne2915684:0:

open

crwdns2934245:0crwdne2934245:0 Michael Epstein

crwdns2947189:0crwdne2947189:0:

iMac not starting after upgrading CPU and pci-e storage

crwdns2934249:0crwdne2934249:0:

Hi,
I attempted to upgrade my 2019 5k 27” imac by changing the CPU and the pci-e storage, and replacing the sata disk with more storage. I bought components and tools from OWC and a new i9 9900K CPU.
I followed the official OWC guide for getting into the imac, which seemed to work quite well, but when I put the components back together and before reattaching the screen I tried to start the imac to be satisfied everything was in order.
I pressed the power button. The fan starts, but there is no POST (or bong noise) and the display is just black.
I’ve looked at the LED diagnostic lights
[image|2404807]
and it looks to my knowledge that LED 2,3 are lit when I power up the imac, LED 2 is lit when the AC is connected. But not LED 1 at any point, or 4 or 5 when the display is connected.
Does anyone know what to try at this point? I have tried reseating the CPU but get the same result. The other things I will try are:
# reseat the RAM (haven’t changed this component thought, and worked fine before)
# put the old components back
Any other suggestions gratefully received before I sent for repair before inevitably deciding it is too expensive to repair economically.
=== Update (05/20/2021) ===
To answer this question - the solution which worked for the '''initial''' question was to reseat the RAM. The five LEDs then lit up as expected and the computer worked as upgraded.
I damaged the display power cable completing the reassembly of the imac - the LED shows the Apple logo on startup but there is no backlight. I can’t determine whether the logic board has been damaged (probably given that the 5th LED is permanently lit as per @danj’s comment), or whether the cable is fried, and I need a new screen. I’m not sure it is worth paying to find out at this point when I have an external monitor which works for sure.
I hope this helps future ifixiters.
+
+=== Update (05/16/2021) ===
+
+Hi Dan, I don't think so though I've had to add and remove the screen to test it[image|2404899] [image|2404912][image|2404901].
+
+I'll have a read through your link, thanks again.

crwdns2866306:0crwdne2866306:0:

iMac Intel 27" Retina 5K Display 2019

crwdns2915684:0crwdne2915684:0:

open

crwdns2934245:0crwdne2934245:0 Michael Epstein

crwdns2947189:0crwdne2947189:0:

iMac not starting after upgrading CPU and pci-e storage

crwdns2934249:0crwdne2934249:0:

Hi,
I attempted to upgrade my 2019 5k 27” imac by changing the CPU and the pci-e storage, and replacing the sata disk with more storage. I bought components and tools from OWC and a new i9 9900K CPU.
I followed the official OWC guide for getting into the imac, which seemed to work quite well, but when I put the components back together and before reattaching the screen I tried to start the imac to be satisfied everything was in order.
I pressed the power button. The fan starts, but there is no POST (or bong noise) and the display is just black.
I’ve looked at the LED diagnostic lights
[image|2404807]
and it looks to my knowledge that LED 2,3 are lit when I power up the imac, LED 2 is lit when the AC is connected. But not LED 1 at any point, or 4 or 5 when the display is connected.
Does anyone know what to try at this point? I have tried reseating the CPU but get the same result. The other things I will try are:
# reseat the RAM (haven’t changed this component thought, and worked fine before)
# put the old components back
Any other suggestions gratefully received before I sent for repair before inevitably deciding it is too expensive to repair economically.
+
+=== Update (05/20/2021) ===
+
+To answer this question - the solution which worked for the '''initial''' question was to reseat the RAM. The five LEDs then lit up as expected and the computer worked as upgraded.
+
+I damaged the display power cable completing the reassembly of the imac - the LED shows the Apple logo on startup but there is no backlight. I can’t determine whether the logic board has been damaged (probably given that the 5th LED is permanently lit as per @danj’s comment), or whether the cable is fried, and I need a new screen. I’m not sure it is worth paying to find out at this point when I have an external monitor which works for sure.
+
+I hope this helps future ifixiters.

crwdns2866306:0crwdne2866306:0:

iMac Intel 27" Retina 5K Display 2019

crwdns2915684:0crwdne2915684:0:

open

crwdns2934241:0crwdne2934241:0 Michael Epstein

crwdns2947189:0crwdne2947189:0:

iMac not starting after upgrading CPU and pci-e storage

crwdns2934249:0crwdne2934249:0:

Hi,

I attempted to upgrade my 2019 5k 27” imac by changing the CPU and the pci-e storage, and replacing the sata disk with more storage. I bought components and tools from OWC and a new i9 9900K CPU.

I followed the official OWC guide for getting into the imac, which seemed to work quite well, but when I put the components back together and before reattaching the screen I tried to start the imac to be satisfied everything was in order.

I pressed the power button. The fan starts, but there is no POST (or bong noise) and the display is just black.

I’ve looked at the LED diagnostic lights

[image|2404807]

and it looks to my knowledge that LED 2,3 are lit when I power up the imac, LED 2 is lit when the AC is connected. But not LED 1 at any point, or 4 or 5 when the display is connected.

Does anyone know what to try at this point? I have tried reseating the CPU but get the same result. The other things I will try are:

# reseat the RAM (haven’t changed this component thought, and worked fine before)
# put the old components back

Any other suggestions gratefully received before I sent for repair before inevitably deciding it is too expensive to repair economically.

crwdns2866306:0crwdne2866306:0:

iMac Intel 27" Retina 5K Display 2019

crwdns2915684:0crwdne2915684:0:

open