Odd situation, Late 2011 A1278 with no signs of life

Discussion in 'MacBook Pro' started by jimanez11, Aug 29, 2013.

  1. jimanez11, Aug 29, 2013
    Last edited: Aug 29, 2013

    jimanez11 macrumors newbie

    Joined:
    Jul 13, 2012
    #1
    Ok, so I recently purchased a late 2011 A1278 13.3" Macbook Pro with slight water damage. When I got the computer home, I wanted to see how functional the computer was. The guy I bought it from said the spill occurred about 8 months ago, so I assumed the main board was dry. I plugged in the power adapter and it immediately booted. No function from power button or keyboard, so I ordered a replacement, installed and pressed the power button and BAM, a perfectly functioning Macbook Pro! Then things started to go downhill... quickly (as they tend to do with electronics) The laptop worked perfectly for about 24 hours and then, in the middle of using it the power down pop-up came up ("Are you sure you want to shut down your Mac?") and then immediate power down. The power button didn't work so I just let it sit overnight. Halfway through the night, I heard the chime and the laptop had turned itself on. Weird stuff...

    The next day, I opened up the computer and began using it again as if nothing had happened. Again, it worked for about a day, then the same "Are you sure you want to power down your Mac?" popup came out of nowhere and the machine powered down. After this, the only way I could coax any life from the machine is by resetting the SMC, which would result in a brief power on period (5 - 10 seconds) and then immediate shut down.

    At this point, I disassembled the machine and cleaned the logic board with 90% ISO, let it dry and then turned it back on using the power button. I ran the Apple Hardware Test and everything passed with flying colors! Then, like the big dummy I am, I selected the Shut-down button after running the AHT and that is the last time the computer has worked. Now there are no signs of life what-so-ever from the machine, no fan spinning, no lights, no superdrive, no nothing...

    This is where the fun stuff starts. The battery still has 7/8 green lights. When the magsafe is plugged in, the light starts green, then changes to amber as it starts to finish out the charge. I have reseated the RAM modules, taken apart the entire machine and reassembled, (logic board, superdrive, hard-drive, speakers, reapplied thermal paste to the CPU/GPU, everything) with no result. I am able to get 16V from the pins on the magsafe adapter (60W power adapter) as well as 3.4V from the "power pads" on the logic board and 3.5V from pin 5 on the keyboard connector. I have tried resetting the SMC (both using the keyboard and the bypass reset) as well as the PRAM/NVRAM. I have also tried "jumpstarting" the machine with no avail. My gut tells me that this is now a bad board, but I am unable to find any signs of corrosion or any blown fuses/swollen capacitors etc.

    If anyone has any other ideas as to what I can do in order to fix this, please let me know. I appreciate any and all help in advance!

    Thanks,

    Jimanez11
     
  2. Astroboy907 macrumors 65816

    Astroboy907

    Joined:
    May 6, 2012
    Location:
    Spaceball One
    #2
    Sounds like just a bad/freaking out power button to me. I think a new keyboard would fix it. The way it sounds now is that the power button is continually in the pressed state. Try jumping the machine with the keyboard disconnected.
     
  3. jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #3
    Thanks for the reply Astroboy, and apparently we think very much alike! I have disconnected all peripherals, one at a time, to rule out hardware (super-drive, hard drive, iSight, keyboard, backlight, LVDS cable) and tried jumping on each occasion with no luck. Just in case I tried it again this evening with just the keyboard disconnected and still, no power or any internal signs of life.

    Also, when I first got the computer I replaced both the keyboard and the backlight, so both of these are brand new. I also reseated the power button to make sure that it was not accidentally installed incorrectly, but the result was the same.
     
  4. Astroboy907 macrumors 65816

    Astroboy907

    Joined:
    May 6, 2012
    Location:
    Spaceball One
    #4
    Hmm. Perhaps it is worth another try cleaning with 90% iso? Now I think it would be corrosion or something on the logic board keeping it from booting (maybe some micro-corrosion if there is such a thing). Try using magnification to check the keyboard connector to see if anything is lodged in it.
    And stupid question, but you never know, are you 100% sure you are using the correct pads to jump?
    Out of curiosity, did you have to replace the backlight fuse? And if so how did you do that? I am in the market for a hot air reflow station and if you had any experience in that it would be awesome to get your advice.

    Edit: by chance, have you tried a complete SMC bypass?
     
  5. jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #5
    I will try to clean the board again with the 90% ISO as you suggested with magnification and let you know. I am almost positive I missed some corrosion the first time I cleaned it. Is there any reason I should try with a higher percentage of ISO, or will the 90% do the trick?

    I am pretty sure I am using the correct jump pads (and thats not a stupid question by any means). I found the following images of the power pads on insidemylaptop.com and hopefully I am reading them correctly.

    [​IMG]

    [​IMG]

    Also, I did not have toreplace the backlight fuse. As far as a hot air reflow station is concerned, that sounds a lot easier than the small butane torch that I have used in the past to reflow Xbox GPUs. If you find a good one, would you let me know. I am not particularly good at soldering, but it is something I would like to get better at.

    Would you suggest attempting a reflow of the GPU, or is that jumping three steps ahead?

    ----------

    Also, by the complete SMC bypass, are you talking about the "hold down the power button for 10 seconds with no magsafe plugged in. After 10 seconds, plug in the magsafe while continuing to hold the power button and hold for additional 10 seconds. Then release the power button, wait a few seconds then press and release the power button." If so, I did try that to no avail. If that is not the complete SMC bypass, would you let me know what that process is?
     
  6. Astroboy907, Aug 29, 2013
    Last edited: Sep 22, 2013

    Astroboy907 macrumors 65816

    Astroboy907

    Joined:
    May 6, 2012
    Location:
    Spaceball One
    #6
    Unfortunately, I don't know. I personally can't seem to find 98% locally, so I only have 91% on hand. If it's what you have, use it. Just make sure everything is completely dry (ports, connecters, etc) before putting power through it.
    Edit: see Dadioh's post about this below, future thread-goers.

    Those look ok, and are in the same locations of the ones here. I think the only difference between an Early 2011 and Late 2011 is a spec bump.

    I'll let you know if/when I get one, but I'm aiming for around $100 but professional systems can run hundreds or thousands of dollars, so I'm being a bit cheap now... I would definitely like to get better at SMT soldering too.

    Yes, jumping way ahead for now. Usually if the GPU is bad the board will boot but nothing will display. I'd say as a last resort :)


    That's the one!

    Edit: at this point some pics of your logic board would be awesome, but you seem to be pretty handy with this stuff and know what you are doing...
     
  7. jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #7
    So I tried cleaning the board again with 99% ISO, (I finally found some in a local grocery store of all places...) which didn't do a thing. After cleaning with a toothbrush I checked over the entire board with a magnifying glass and couldn't find anything as far as corrosion or missing transistors/resisters, etc. After putting it all back together, I got the same result. When power button is pressed, nothing happens. No fans, no lights, no nothing...

    Also, I am not sure if I mentioned this earlier, but if I do a PRAM reset, the magsafe light will briefly turn from amber to green. This means that the keyboard is working fine and that the logic board is still receiving good power throughout. I have checked the LCVD cable and everything looks fine as far as that is concerned as well.

    Any ideas for potential next steps? What should be checked/potential problem areas...

    Thanks!
     
  8. Dadioh macrumors 65816

    Dadioh

    Joined:
    Feb 3, 2010
    Location:
    Canada Eh?
    #8
    90% or 99% won't make a difference. The idea is just to dissolve contaminants. Actually the 90% would be better if the contaminants are only water soluble. The alcohol just dries a lot faster than water and reduces the water surface tension to allow finer cleaning.

    There are quite a few things that can be wrong for a board not to boot. You know you have 3.4V on G3Hot so that is a good start. I would next check to make sure the 3.3V supply is putting out 3.3V. It is a dual port device with the other half putting out 5V but 5V is not enabled until later in the power up sequence.

    Also, the battery is known to be good? Putting out 12V even without the MagSafe plugged in? Check Pins 4 and 6 on the battery connector with battery plugged in. Those are the i2c bus connections. They should measure about 3V.

    Some things to try anyway.
     
  9. Astroboy907 macrumors 65816

    Astroboy907

    Joined:
    May 6, 2012
    Location:
    Spaceball One
    #9
    I stand corrected, sorry for any misleading I have done. Thanks, Dadioh!

    As for the board, at this point pics of your actual board would be at least a little more helpful. Not 100% sure I will be able to help, but worth a shot.
     
  10. jimanez11, Sep 21, 2013
    Last edited: Sep 21, 2013

    jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #10
    Thanks for the response Dadioh and please forgive my electrical ignorance, I was a business major... I am not sure what exactly you mean when you say "It is a dual port device", but I measured each pad of G3HOT separately and I got 3.4V from the right pad (with the battery closer to me), and 0.0V from the left which is hopefully close to what you were talking about.

    I was able to take measurements on pins 4 and 6 of the battery connector with the magsafe unplugged and I got 3.5V from both of them. Before the laptop died on me, I was able to use it while running on battery for a decent amount of time, so the battery appears to be in good shape.

    I am about to post a few pictures of the Board that I took this morning per AstroBoy's request. One of the pictures has a few labels of some additional measurements I took from the board.

    Thanks again to the both of y'all for helping me out with this. It is by far the most in-depth repair I have attempted so far.

    Front of Board

    Back of Board
     
  11. jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #11
    The last thing I would say you did was mislead anyone. No need to apologize!

    I placed a few links to pictures of the board as you suggested along with a few random points that I measured. (I have no idea which points, if any, were pertinent or informative...)

    Thank you again for taking a look at this!
     
  12. Dadioh macrumors 65816

    Dadioh

    Joined:
    Feb 3, 2010
    Location:
    Canada Eh?
    #12
    By dual port I meant the the one power convertor does 2 voltages. One half is used to generate 3.3V and the other does 5.0V.

    Before the board starts you should see 3.3V output. The 5V output only happens once the board starts the power up sequence.

    Try measuring on the capacitors around the device labeled. You should see 3.3V output.
     

    Attached Files:

  13. jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #13
    Thanks for the explanation! I have measured the capacitors surrounding the 3.3V/5V Supply and I am not getting 3.5V, but instead a wide variety of measurements from 0.0V to 12.2V. Also, the two black capacitors North and South of the 3.3V/5V Supply, when initially measured, started with a charge but quickly drained to 0.0V.
     

    Attached Files:

  14. Dadioh macrumors 65816

    Dadioh

    Joined:
    Feb 3, 2010
    Location:
    Canada Eh?
    #14
    Ok. Looks like you are not getting 3.3V out of that supply. If memory serves me it would be the cap on the right side of the chip that should have 3.3V. I would suggest powering off the board and the. Use a multimeter to check the leads of that device and compare to schematic. Make sure nothing is shorted to ground.

    At this point you are into some troubleshooting that requires advanced skills. Unless you see something obvious. But your board will definitely not boot without that 3.3V rail.
     
  15. Dadioh macrumors 65816

    Dadioh

    Joined:
    Feb 3, 2010
    Location:
    Canada Eh?
    #15
    Had a bit of time so I looked at your voltages. The device is getting the 12V it needs to generate 3.3V and 5V but the enable pin for the 3.3V supply is low. In order for the 3.3V to enable it requires P3V3S5_EN_L to be pulled low, turning off the FET and thus allowing P3V3S5_ENTRIP to be pulled up to 3.3V. Since you are seeing 0V on P3V3S5_ENTRIP then I assume that P3V3S5_EN_L is high so U7941 is not passing through the enable signal from the SMC. This requires some high end troubleshooting skills unfortunately. I have shown some excerpts below that identify what I am talking about if you want to study the schematic but if you are not an electronics person it may not be helpful. But maybe it will help other readers.

    Good Luck
     

    Attached Files:

  16. jimanez11 thread starter macrumors newbie

    Joined:
    Jul 13, 2012
    #16
    So, based on your suggestion to ensure that there was nothing shorting out to ground (corrosion would be my guess as this was a water damaged board) I gave the board a prolonged ISO bath and a good scrub with a toothbrush and put the whole thing back together. This upped the voltage on P3V3S5_ENTRIP to 1.3V (still not 3.3V) and it pulled up the voltage on quiet a few additional caps that were surrounding U7200. I will take it apart again at some point today and measure P3V3S5_EN_L (which is on the back of the board if I am not mistaken...) and to o see if U7941 is passing correct voltage through to P3V3S5_EN_L. I will take a loot at the schematics and see if I can trace the issue back to a particular certain cap. I am OK at soldering (have repaired guitar amplifiers and DCIN boards on computers), so I am up for trying to solder on capacitors if one has blown.

    I will let you know what I end up finding, if anything!
     
  17. guanaco4life, Sep 27, 2013
    Last edited: Sep 27, 2013

    guanaco4life macrumors newbie

    Joined:
    Sep 27, 2013
    #17
    bridge pin number 5 and 29 from the keyboard connector and that will turn on the board. and the problem with the mac trying to shut down is the bad keyboard.once you remove the keyboard it won't ask to shut down, connected back and it will shut down.
     

    Attached Files:

  18. Dadioh macrumors 65816

    Dadioh

    Joined:
    Feb 3, 2010
    Location:
    Canada Eh?
    #18
    Pin 29 is ground and Pin 5 is just a 1K resistor to SMC_ONOFF_L which is the jumper pins. In other words, using the jumper pins achieves the same thing that you are describing with the keyboard pins. He has already tried disconnecting the keyboard and starting with the jumpers.

    He may well have a keyboard power button issue as well (indicated by the early symptoms) but at the moment the keyboard is removed so there is another issue. As I said earlier, he is missing 3.3V so that power supply requires repair before this board will start.
     

Share This Page