Hi forum,
I dumped the fw and modified it according to the tutorial, but after reflashing the chip, the machine won't start. Fan spins up, then spins down in about 10 seconds, then the cycle repeats endlessly. No chime, nothing on the screen. Tried several key combinations (various reset). Nothing works. I attached the original dump, the modified dump, then the dump for this model found in repo, and the modified repo dump. Could anyone look into them if they are modified as they should? I might have missed something.
reverendalc wrote: Your programmer, is it capable of 3.3v?
Most IC programmers I've seen only do 1.8v. If your power was too low, then the original read was bad.
Always read the chip several times and compare their md5 checksums.
If you flash back the original read, will the MacBook boot?
Yes, it is, I even hooked up an oscilloscope to see if it drops voltage during reading/writing. Lowest drop was 3.23V. Laptop battery was disconnected during the read and write. Lesson definitely learned regarding multiple reads. I tried to flash back the original read, it doesn't boot, no chime, no video.
reverendalc wrote: I am at work and unable to inspect your ROM on my phone, but have you tried cleaning the ME region of the repo copy and write that?
That should in the very least get you a chime. If not, we seem to have a communication problem with the chip.
Which chip do you have? Does your programmer identify the flash chip correctly?
Didn't know about ME region. The programmer has identified the chip as being MX25L6405, which should be for this model. Since we talked I went the RPi route, chip also identified as the above mentioned one.
reverendalc wrote: Ok that's good. There's a blog on here about cleaning the ME region. Try that.
Also, try dumping with the rbp three times and comparing their checksum.
Well, found that blog, the MEA Analyzer link is dead, found it on GitHub, it's a python script, I installed the missing libs, tried to run that file against the original dump, but that python script is so full of errors that I couldn't get it to work. So basically I don't know which file to download. Tried to identify it by trying to find the chipset using various "serial number decoding" sites. None of them had the info I was interested in. Is there any similar tool that I can use?
I'll have to look into it when I get home, but just a thought:
The Apple download page for EFI updates...
Perhaps a google search of the EFI version might yield some info about the ME?
Also, in the comments section of the ME blog, king bone crusher posted a neat idea worth trying. You could try it with various ME regions, or even experiment adding them to your dump. Just be sure to keep a backup of the original (-:
reverendalc wrote: I'll have to look into it when I get home, but just a thought:
The Apple download page for EFI updates...
Perhaps a google search of the EFI version might yield some info about the ME?
Also, in the comments section of the ME blog, king bone crusher posted a neat idea worth trying. You could try it with various ME regions, or even experiment adding them to your dump. Just be sure to keep a backup of the original (-:
Well, that road took me nowhere near to my goal Had a hard time unpacking a dmg on linux, but eventually I did, but found nothing that I can use in my case. I do not have another mac. I'm not sure trying different ME regions is such a good idea, considering you interact with hardware almost directly, it could really mess up things. I remember one time when rewrote a firmware in a piece of hardware which had a smart charging based on PWM, few chips blew up because of incorrect values.
There isn't any chance you changed the RAM module(s) while you had it open is there? Just ask, because I've had instances where a MBP would exhibit the symptoms you site when it wasn't happy with specific SODIMMs used in an upgrade for whatever reason.
reverendalc wrote: It's very difficult and requires advanced reworking skills to remove ram chips on MBA as they're soldered to the mainboard.
Not very likely lol.
I apologize if I've already asked, but can you provide your board model no and I'll see what I can scrape together?
It's 820-XXXX.
My bad, the post title states MacBook Air and I was thinking older MacBook Pro (MBP). Guess it helps to read and think before posting. Didn't mean to create confusion.
reverendalc wrote: It's very difficult and requires advanced reworking skills to remove ram chips on MBA as they're soldered to the mainboard.
Not very likely lol.
I apologize if I've already asked, but can you provide your board model no and I'll see what I can scrape together?
It's 820-XXXX.
Where should I find that? I've looked all over the motherboard, couldn't find anything that resembles that. The serial number check didn't yielded anything like that also.
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