For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
Whenever I try to measure CPU_VR_READY the computer shuts off. This happens anywhere that I try to read that signal on the board... just putting my probe on the pad causes the computer to power down. I replaced U7200 to see if it was the problem, but nothing changed. LPC_PWRDWN_L is not...
I got my CH341a programmer up and running. I just uploaded a new bios with clean ME region and the computer still will not boot. The computer has exactly the same symptoms as before... fan spins, stops and then just keeps spinning. No boot.
PLT_RESET_L is still missing. At the top of pg. 13 of...
Thank you Piernov that was helpful.
I need to put a new bios onto a 2015 820-00165 board using the process you outlined above. On the forum I was able to find a 2017 820-00165 bios with a clean ME. Are they compatible? I was unable to find the file for a 2015.
Thanks
I did some research... does this seem correct?
1) Start with a good BIOS with clean ME region for your motherboard (in my case 820-3115)
2) In HxD, calculate the checksum (Apple uses SHA-1 format) prior to making any changes. Record this number.
3) Change the serial number to the correct value...
I have a few computers that I suspect have a corrupted bios (they don't boot) so I do need to build a new one.
I can correct the serial number myself using HxD.
How do I fix the checksum of the Fsys area?
I take it back... for some reason the search function didn't work initially. I tried it again and found the serial number hidden among all of the gibberish.
Can I get clean bios files for 820-3115 and 820-00165?
Also, I know that you can't take a bios chip from one motherboard and transfer it...
I extracted the file (PE32 Image Section) and opened it with HxD. I attached a screenshot. For the most part, the decoded text is just nonsense. I feel like I'm doing something wrong though because when I open up a known working bios file in HxD the decoded version is also not intelligible.
I downloaded UEFITool NE and searched for SSN. It specified the following destination: EfiCrc32GuidedSectionExtractionGuid/PE32 image section at header-offset 314Ch. After navigating there, the contents did not show anything related to the serial number. I attached a screenshot. What am I doing...
I extracted the bios from an 820-3115 MBP using a CH341a programmer. Is there a program that can get this into a readable format so I can see basic information about the computer (ex. serial number)?
Thanks
I am on my third SMC replacement and can't get green light back (I had green light prior to replacing SMC). I don't know if I just have a bunch of salvage boards with bad SMCs or if I caused a new problem during the replacement.
The following signals are present:
PP3V42_G3H
PPBUS_G3H reads a...
This machine was water damaged. ISL 6259 was replaced and battery current sensing was repaired. Overall, damage was minimal. It now passes ASD EFI without issue and runs well. Only hardware that has been changed is HDD has been replaced by non-Apple SSD.
Sometimes, when the machine is allowed...
Thanks for the schematics.
I spent a while digging through Google search pages but all of the links I found were either broken or had no seeders.
The closest I got was this:
https://www.loremipsum.info/2019/03/apple-service-diagnostics-mac-test-pro/
I was able to download the files, but...