MacBookPro A1502 820-3536 kernel panic.

[Francisco.s]

Hi, this MacBook boots with its internal ssd a bit slow.

With a windows based boot disk, it boots witout problems and with normal speed.

I've tried to boot from asd 3s162, and it boots but shows a message of kernel panic "failure missing me".

With asd162 "EFI" didn't pass "Management engine presence test".

I have tested two different clean ME bios and the problem's still the same.

Any hint to solve the problem?

Thanks in advance.

[piernov]

Re: MacBookPro A1502 820-3536 kernel panic.

If you're 100% sure ME region has been cleaned properly, check/replace Q1920.

[Francisco.s]

Re: MacBookPro A1502 820-3536 kernel panic.

check/replace Q1920.

Thanks piernov for your quick answer.

I have no other dual mosfet for replace Q1920, but al voltages seems to be good in its pins.

pin 3= 1.5 volts
pin 2= 3.4 volts
pin 4, 5, 6= 0,01

SPI_DESCRIPTOR_OVERRIDE has no voltage. (I think it has to be at high level in order to write the ME region)

Bios dumps are downloaded from other internet forums and marked as "cleaned".

I will try to clean the original bios and post if it solve the problem.

Have you seen this messages before?

[Francisco.s]

Re: MacBookPro A1502 820-3536 kernel panic.

If you're 100% sure ME region has been cleaned properly, check/replace Q1920.

As I was not 100% sure about ME region, I made my own dump cleaning the original dump, but something went wrong and it didn't boot.

So I decided to test other bios from this forum, and by mistake downloaded a dump from this link: https://www.badcaps.net/forum/showpo...4&postcount=14

At first didn't notice that this bios is for a 820-3476-A, not the 820-3536.

The weird thing is that it chimes with no delay, and boot asd without kernel panic.

Asd362 now boots and makes all test,but sows a few errors:

Local machine info: Mac OS X version = 10.9(13A3017) IP Address:127.0.0.1 ASD version:3S162
==========================================================
==========================================================
ASD Log activity from [06/22/20 16:22:41] to [06/22/20 17:13:44]

--------------------
- Verifies that a correctly formatted system serial number has been burned into the unit.
[16:22:42] Test Passed
[06/22/20 16:22:42] * All startup tests passed [Elapsed time = 00:00:00] *

---------------------------

[06/22/20 16:34:10] * TESTING STARTED *
[06/22/20 16:34:10] Boot ROM: Boot ROM FW GUID MAC Addr Checksum Test (test #2) - Boot ROM FW GUID MAC Addr Checksum Test
- Verify the Boot ROM FW GUID MAC address checksum.
[16:34:10] Test Passed

-----------------------------

[06/22/20 16:34:16] Sensor Group (test #5) - Limit with Core Load Test
- Verifies a group of sensors defined in SensorGroupLimits.prm. The test will generate two loads - cpu and gpu - then verify the list of sensors per limits.
[16:35:08] Sensor Failure=[Current (ID0R) -- DC In] Faild Value=0.008789
[16:35:10] Sensor Failure=[Voltage (VD0R) -- DC-In] Faild Value=0.000000
[16:35:10] ERROR -- 3 [Sensor reading below low point] -- TEST FAILED

----------------------------------
I dont know if this errors are problems from board or they are because incompability bios issue. (this board has had spilled coffee in the past)

At least, seems that pch and smc are not damaged.

I will test the circuits involved an will post the results.

[piernov]

Re: MacBookPro A1502 820-3536 kernel panic.

Make sure Magsafe is plugged in properly and there is no bad contact in the connector during the test.

[Francisco.s]

Re: MacBookPro A1502 820-3536 kernel panic.

Asd362 now boots and makes all test,but sows a few errors:

Seems that ASD 3S162 is a bit buggy, as I've read from other forums.

Finally I have repaired the "ME region" from original dump, and all is working properly.

ASD 3S162 keeps showing weird errors.

Some weird errors:

- Verifies PCIe root port error bits for wireless module doesn't register any NAKs
[16:41:17] ERROR - -12100 [IOConnect error reading from PCI address space] -- TEST FAILED

- Checks the SATA link error registers for dropped data packets using direct PCI access.
[16:41:18] ERROR - -12105 [PCI driver IOService open error] -- TEST FAILED

- Verifies that a unit can automatically sleep and wake using the OS sleepx tool with 30/60/1 settings.
[16:48:31] ERROR -- 11 [Invalid wake event] -- TEST FAILED

These are as an example, but there are a few more.

So the problem was bios corrupted, but only in ME region.

Thanks your valuable help.