Mac Pro 4,1 (flashed to 5,1) Problems updating firmware for High Sierra

[Zeke]

I read about this before attempting and everything I saw indicated the flashed 5,1 had no issues with this.

For reference, I have a 4,1 that I updated to 5,1 to take the Xeon W3690 (single processor 6 core 3.46Ghz) processor. I flashed a Sapphire Radeon R9 280x with EFI so I was able to get boot screens. System boots off of a (non-apple) SSD.

Last night, I went to install High Sierra and when prompted to shutdown and hold power button for firmware update, I got the flashing light and long tone and then nothing. Computer is powered on, but I have no signal to monitor. Is this a known issue with flashed GPUs? I no longer have the GT120 to see if that's the culprit now. I don't want to throw a bunch of money trying things if it's somehow bricked.

Any thoughts?

 

[h9826790]

I read about this before attempting and everything I saw indicated the flashed 5,1 had no issues with this.

For reference, I have a 4,1 that I updated to 5,1 to take the Xeon W3690 (single processor 6 core 3.46Ghz) processor. I flashed a Sapphire Radeon R9 280x with EFI so I was able to get boot screens. System boots off of a (non-apple) SSD.

Last night, I went to install High Sierra and when prompted to shutdown and hold power button for firmware update, I got the flashing light and long tone and then nothing. Computer is powered on, but I have no signal to monitor. Is this a known issue with flashed GPUs? I no longer have the GT120 to see if that's the culprit now. I don't want to throw a bunch of money trying things if it's somehow bricked.

Any thoughts?

Flashed 280X can do all 5,1 firmware update.

Anyway, do you mean that your cMP only fail to update the firmware? Or fail to boot now?

 

[Zeke]

It chimes when I hit the power button but I see no image on screen. I assume it failed to do the firmware update but I can't break out of it now.

Flashed 280X can do all 5,1 firmware update.

Anyway, do you mean that your cMP only fail to update the firmware? Or fail to boot now?

 

[h9826790]

It chimes when I hit the power button but I see no image on screen. I assume it failed to do the firmware update but I can't break out of it now.

Did you try reboot the monitor, check the cable, etc?

It chimes means it pass the POST, so, the firmware must be good now.

 

[Zeke]

I'll give it a shot but when I hit the power button when it's been stuck it immediately powers off unlike if it's successfully booting (where you have to hold it down to force shutdown). After holding the power to get the flashing light, long beep I've never seen anything on the display (including the gray firmware update status) so I'll be a little surprised if it's somehow randomly that the cable is doing something weird. I'll try different monitor and cable tonight to rule it out.

Did you try reboot the monitor, check the cable, etc?

It chimes means it pass the POST, so, the firmware must be good now.

 

[h9826790]

I expect you already try PRAM reset, right?

 

[Zeke]

Not yet. That was first on my list but I'm hunting for my wired keyboard that is currently MIA.

I expect you already try PRAM reset, right?

 

[h9826790]

Not yet. That was first on my list but I'm hunting for my wired keyboard that is currently MIA.

From your description, a simple PRAM reset may actually able to fix it.

 

[Zeke]

I found my wired keyboard, changed the wiring on the monitor to a VGA cable, unplugged a bunch of stuff and tried resetting PRAM several times and also SMC. I don't know which combination ended up working but after some hiccups I finally got video feed to see the firmware updating. Thanks for the help!