820-3437 Wont boot Part 2

rsiesta

New member
I have a board that was liquid damaged, stuck in boot loop. I installed a new bios chip and now it chimes and will start booting.

Any attempt to load macos results in progress bar to 3/4 then slows down greatly,
it eventually gets to the end of the progress bar and then just stays there.

After fighting this for days here is what I have found.

hold D and running Diagnostics finds no problems other then needs new battery soon.

Booting off a High Sierra recovery partition has same result freezes at 100% progress bar.

Execute an internet recover runs fine, all recovery options seem to work. I select reinstall OS and it proceeds
to downloading mountain lion and install it. This all runs fine, It completes successfully I do the final
reboot and same thing, hangs at end of progress bar. I can now run the recovery partition, ie a ML recovery
program will load/run where as the HS would not.

Next I create an Ubuntu Live disk, runs fine, I then install Ubuntu 18.04 to the internal SSD drive, works fine
ubuntu starts and runs no issues.

A Hardware issues I have found. When you plug into the display port/thunderbolt port you get no boot screen when
trying to start macos. Under Ubuntu it detects the port, It correctly detects the monitor size and brand, the internal
screen flashes like it normally does when adding another display but nothing on the external monitor.

Under Ubuntu when I plug in a thundebolt drive it does not power up and is not detected by Ubuntu. The thunderbolt
port is detected in the hardware settings.


So something wrong with the thunderbolt/display port. I am guessing this is what is causing MacOS not to boot.

Any thoughts, can you change the thunderbolt chip from a donor board?
 

rsiesta

New member
Done it myself, same affect, Bought a new bios with clean ME region, same result, now I can see me screwing up the flash but I would think that someone that
sells them for a living would have it right. I know he got the serial number correct as the requested serial number show up after running the Diagnostics on the new chip.
This is the one I bought based on the serial number I got when I downloaded the bios from the bad chip.

https://www.ebay.com/itm/EFI-BIOS-Fi...72.m2749.l2649

The serial number also matches the bottom plate which is rare. I am game to try again but don't know another way
to attempt it.

This is what I got from the bad bios after I downloaded it off the original chip

override-version..Base_18..kcal..US.ssn..C02MXMLEG086.hwc..G086.son..MD761LL.EOF
 
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2informaticos

Administrator
Staff member
I think on the forum we have already uploaded clean dump for 3437.
Use it as is, just for test.
If all OK, then you can change serial.
If try to change it yoursels and is not dome properly, you cannot discard BIOS issue.
STOP to buy dumps from eBay; 90% are not clean at all.

Your symptom points to ME region issue...
 
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