Chip replacements identify

[jagiro]

Hello guys/girls ,i am new to this forum.

I am curious about one thing.

this is the story. i had a broken imac 24 inch from the early 2009. it turned out to be a corrupted UEFI bios.
now my mac has been repaired. i ordered anther chip online(which this guy reprogrammed with healthy firmware) and i did the resoldering my self.

now my question is this, and what i would like to learn is. how did this guy, from england knew, what empty chip to order that will fit into my mac . all he needed to know is, my imac model and serial number. where did he look up this information into what chip is inside my imac?

lets say my imac broke again. and i had the equipment to reprogram another empty chip to replace my broken one. how will i know which empty chip to order online.

thanks!

[PA0PBZ]

lets say my imac broke again. and i had the equipment to reprogram another empty chip to replace my broken one. how will i know which empty chip to order online.

I would be surprised if it's not the same chip you just replaced 

[amyk]

Almost all BIOS are stored on very common types of flash chips --- earlier motherboards used DIP parallel EEPROMs, then PLCCs, and the latest use tiny SPI ones.

As for the contents, you can easily find that online too.

[theatrus]

And if he is in the business of flashing boot flashes, he probably has several iMacs open up on his bench