Will an iMac boot if EFI is bad or fried?

[zataralos]

changed the EFI chip (firmware lock) on my iMac and now it won’t boot. Symptom is LED1 on, LED2 flashing every 5 seconds. The PS seems to be ok, I can measure 12V getting to the logic board. Power button does nothing. Before I start looking for shorts, etc, wondering if the new chip is either bad or fried during installation. It's a 2017 21.5 4K model.

Thanks

 

[aangvento]

I am not familiar with this motherboard specifically, but... Without the EFI the computer shouldn't be able to boot, no. Unless it's a specific case, it shouldn't be able to boot.

 

[zataralos]

I am not familiar with this motherboard specifically, but... Without the EFI the computer shouldn't be able to boot, no. Unless it's a specific case, it shouldn't be able to boot.

thanks, so I re-soldered the old chip (was working before) and getting same behavior. I found the datasheet for the EFI and checked voltage between VCC and Ground and am getting the right supplied voltage 3.3V. So the chip is connected correctly just missing the actual firmware? would over-heating the chip destroy the storage but not the electrical components?

 

[Nguyen Duc Hieu]

Maybe there's something you need to do with the EFI chip, beside desoldering + soldering.
You might take a reference from the following video:

 

[aangvento]

Yes. The chip does have a program inside it and you do need said program tk make it work.

thanks, so I re-soldered the old chip (was working before) and getting same behavior. I found the datasheet for the EFI and checked voltage between VCC and Ground and am getting the right supplied voltage 3.3V. So the chip is connected correctly just missing the actual firmware? would over-heating the chip destroy the storage but not the electrical components?

However, this program is something apple will likely not allow you to install on your own. Did you buy a new chip or did you get it from a donor board? It only works if you take it from a donner board.
Tell us how it went!

 

[zataralos]

Yes. The chip does have a program inside it and you do need said program tk make it work.



However, this program is something apple will likely not allow you to install on your own. Did you buy a new chip or did you get it from a donor board? It only works if you take it from a donner board.
Tell us how it went!

Bought a new chip, newly programmed so it should have worked. since I get voltage at the VCC i know it's not a power issue. Wondering if overheating the chip would have caused it to fail . BTW - subscribers to NorthridgeFix

 

[aangvento]

Bought a new chip, newly programmed so it should have worked. since I get voltage at the VCC I know it's not a power issue. Wondering if overheating the chip would have caused it to fail . BTW - subscribers to NorthridgeFix

I mean, overheating the chip can destroy it yeah. You can melt it for example. But it is not likely, ain't not usual. I know for sure that some chips you need to take from a donor board or they won't work because the programming isn't the same or some other reason. is the chip itself working? Is voltage going through it correctly and so on?

 

[zataralos]

I believe I purchased the right chip. Company who specializes in unlocking BIOS and confirmed it's the right chip for the board. They're sending me a new one, will see if that one works

 

[aangvento]

Alright, keep us updated then, please!

 

[boogie89]

any solution for this issue?
Replaced the efi chip on my MBP2017 A1708 and now it won't boot anymore.