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[SOLVED]A1466 emc 2559 - dong loop after failed external drive boot

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Joesipaq

New member
Hello all. Received a working MBA the other day, along with a new MB to do a data transfer too.
Transfer went fine using migration assistant.
Last night I left the MBA on doing a time machine back before wiping it and installing high Sierra.
Booted fine this morning, stuck in my live thumb drive that has high Sierra to install.
Booted to efi partition - hung on Apple bar screen at about 90%
Pulled thumbdrive and powered off the machine. Switched USB ports, option - per and once the apple dong stops - it dongs again and again.. Indefinitely.

SMC reset and pram reset didn't do anything to help.
Pulled ssd, wifi/bt, battery. Still same symptoms.
​​​​
Any suggestions on where to go from here?

Only previous work history reported from user was due to 100% full ssd. Had the apple store clear it up for her. I do see some fingerprints on odd places internationally though. Going to pull the motherboard and check for any heat damage/probably bios area first.

Ill keep you guys posted and give you the motherboard number once I get the board out. (820-3209-a)

Update: fan spins fine. Isl sense resistors are ok, no water damage anywhere. Bios resistors are reading what I would expect. Going to bust out the microscope and bv/schem to start checking voltages, but not sure what to look for in this case.
 
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J

Joesipaq

New member
Ok. All apart, on my bench, one speaker hooked up. After going over the whole board, looks perfect. A few to look like they got some heat around the R5127 area.
Oddly, Q7801 looks like it's on upside down... Ground pad is on top (see pic) not the problem as it's been like that - but my 3 doaner boards have a normal looking FET. Out of curiosity, kina looks like trace Flux on the board? Would this be typical of a refurbished board?

Decided I'd try a boot, seems to be working fine... Wtf. Going to test in housing. I didn't unplug the Webcam in my first tests. IMG_20171116_110152.jpg
 
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J

Joesipaq

New member
Update #3
Put back into housing - Chime loops again. Started testing with lest and less attached. Screen seems to be causing the issue? LVDS Cable has a 0 written on the bottom of it with a silver marker. Looks like the screen or cable is a replacement. Did I just have a clients screen crap out on me? On to measurements for the LVDS connector.
 
D

dukefawks

Administrator
Repeating chime is usually a RAM issue. I bet this is a 2011 board, they are infamous. Don't even bother to try and fix it.

Seems unlikely it is the LCD but it is of course possible. Try a known good assembly.
 
J

Joesipaq

New member
I sure hope it's not a goner... Here is the sn.C02D2QCLDRVC. Because it was introed in 2011, would that essentially make it have a 2011bd instead of a 2012?
I'm not someone that wants to play the ram game :( on a personal level, how would you recommend I talk to my client about it.. She brought me a working unit that died with normal use for me. Or am I going to be out a few hundred to get her a replacement?
 
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dukefawks

Administrator
It's a 2012 board, those are less common than the 2011 with RAM issues. If you disconnect LCD it does not echo? External LCD working?
 
J

Joesipaq

New member
Woah! Missed this update... Dang. So, with LCD disconnected it does not echo - and I don't have one of those fancy dongles yet for testing an external monitor. I did order a parts computer with a cracked but working display and a "good" motherboard based on the theory of the ram dying - Guess I should invest in an adapter for a display eh?
Will the generic ones work, like the amazon basics versions to hdmi and to vga?
 
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dukefawks

Administrator
No idea if they work. I just got the original ones so I know 100% sure it works. I'm not going cheap on that and cause frustration with Chinese garbage.
 
J

Joesipaq

New member
Ok... What the fack.... So, today i got my replacement mobo/test machine. Poped the old mobo in to the working houseing - same problem - so not the screen. Pop the replacement mobo into the old computer, works perfectly

Install SSD, all is good. Boots and all. No obvious issues.

Client wants unit cleaned and installed to high sierra. No problem, right?

Format SSD, go to install High Sierra from my thumbdrive (using UniBeast) - Says there is an error - Boot while holding D says the 4hdd/11/40000whatever. Run First aid - its ok. Try to reinstall from scratch again same issue.

Pause here for dumb question hindsight - Is there a difference between the versions of sierria I would download from the app store depending on if it was from a macbook, macbook pro or macbook air? These sierra and high i have were downloaded from the app store on my macbook (old af edition)

Plug Sierra install usb in to usb on charging board, (same as before) Try installing, all seems to go great, get to the point where it says to restart to complete install (didnt get this far originally). Do so - System hangs at white screen for like 25 min... no apple logo or nothing... Rebooted.... Same - pulled ssd, same. No chime this time, no response, Dead fkin motherboard again... WTF? Pram and smc reset dont do anything at all. No charger change, and no reboot for pram.

Is this something that is messing up the SMC while trying to write or such to it with the update? Not sure if that even takes place... What do you think duke? or anyone else?

Thanks!
 
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J

Joesipaq

New member
Quick update -
SMC reset with no battery - light goes from amber to green, then the moment amber again, the screen turns on and just hangs still.

If, while the screen is on - cmd, opt, shift, power - like an smc reset but the system is on - The screen instantly turns off - amber light goes green, the repeat.

My gut is saying that somehow, during the update the SMC is getting wiped and not written to or something with the smc... or bios? Looks like I have 820-3209 doaners with smc and bios...
 
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J

Joesipaq

New member
Brain juices flowing - 4hdd/11/4 error with high sierra... I don't know how the updates work. I am going to take an educated guess and say that during the update process, the SMC is updated too with new code? So, SSD problem could potentially cause a failure to write valid/new info to the SMC? Shooting in the dark here. This will be a good lesson learned though. I'm pretty sure I will need to replace the SMC to get this to boot again, but the root cause, is the SSD?
 
J

Joesipaq

New member
this is 2 different boards now though... Both all of a sudden came down with bad ram or a randomly cracked trace?

I mean, I just bough this board and received it today working. Sure, it wasn't new - but that's the original working board and now this replacement board both died while I was in the update process with the same SSD
 
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J

Joesipaq

New member
I did, but as I mentioned, now both boards hang before the apple logo - With or without SSD or other boot media
Ill clifnote till now

Original working board - Was working perfect for 3 years, no prior repairs or problems. Basic data transfer and reinstall job. Tried to load from sierra installer usb - Hung - gave chime echo no apple logo. All work was done in a warm environment- maybe failed ram due to heat?... ok

Replacement working board purchased, all done in nice air-conditioning- Booted ok from original ssd, passed basic diagnostics (d key) High sierra thumbdrive installer failed with "something wrong with system press D while booting" thing, Did that, Gave HDD generic error - Ran first aid from recovery - said it was ok. Tried again, with High sierra, same error. ---- Tried installing sierra, went perfectly. Got to "reboot now to finish" Rebooted, hung at white screen. Waited 25min, rebooted and same thing. PRAM reset doesnt trigger, SMC reset doesnt resolve.

Odd thing with new replacement board, when it is on and hung in the white screen w/o battery installed, pressing smc reset keys and tapping power button initiates smc reset. Never seen that before.

Could a bad ssd cause a corruption to the smc update sequence durring osx install?

That is where my mind is now.
 
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dukefawks

Administrator
I would more suspect a corrupted ROM than SMC. Try a known good dump and then fix the ME region. Keep the original!!
I dunno what you mean by SMC reset keys, but you need to press shitt+ctrl+alt+power to reset SMC, but without battery and disconnecting power is of course exactly the same..
 
J

Joesipaq

New member
I can't ever remember the key names, just the patern. SMC reset keys meaning that exactly, shift+Ctrl+alt then touch power - while screen is on - and the SMC reset initiates. That I found odd.
Holidays here till Monday, will pull the BIOS and take a read, should I trust my doaner board/s for a good read?
 
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