cMBP 13-inch mid 2012 strange problem

I am trying to diagnose random freezing of this MacBook Pro.

In short - laptop freezes in about minute or two after boot.

ASD says that everything is OK, including RAM.

What I tried:

- Swapped RAM sticks with 100% good ones
- Different boot drive with different OS (10.8 and 10.10)
- Swapped internal SATA cable
- Disconnected optical drive, WiFi + BT module + battery
- Disabled all Energy Saver options
...and so on

And now interesting part:
MacBook keeps working fine with external FireWire disk connected

Any ideas ?

SlCKB0Y said:

What do the system logs say prior to the freezing?

I would reset SMC and PRAM:
http://support.apple.com/kb/PH14222?viewlocale=en_US
http://support.apple.com/en-au/HT201295

Then I would boot into safe mode and see if the problem continues:
http://support.apple.com/kb/PH14204?viewlocale=en_US

Click to expand...

Thank you for quick reply.

SMC and PRAM reset - done, same problem.

Safe Mode - works few minutes longer but still freezes.

System Console / Log do not say anything special, normal stuff. No error, exceptions, panics, nothing.

I just found out that laptop works fine with USB disk connected as well as FireWire.

So this look like mounted external drive prevents something to happen, most probably one of power management tasks.

SlCKB0Y said:

Does it make a difference if it is on battery or power?

Click to expand...

New Interesting thing is that laptop works fine when battery is connected and its charged 100%. When laptop is used on battery and its charge falls by 2-3% (98-97% full charge), then freezing starts again. Battery doesn't charge then, because it's borderline for full charge.

Currently draining battery to check what happens when it's completely empty.

Ok. Here are some updates:

It was on for 2-3 hours with FireWire HDD connected, no freezes. Stressed by YES command in terminal for a while to quicken the discharge. Everything went smoothly. Battery went to 0%, system dumped memory to disk and shut down.
I've disconnected the FW HDD, connected power adapter and started the computer. Froze relatively quickly (less than a minute).

Re-did PRAM and SMC reset, no change. Still hangs very quickly after boot.

One more interesting thing: while frozen, when I close the lid, sleep LED lights up, but nothing else happens. Screen and keyboard are still lit. When I open the lid, sleep LED shuts off and computer is still frozen.

I've noticed that my SMC version is 2.2f41 and latest for my cMBP is 2.2f44, but it refuses to update with message: Not supported on your system.
Also, my EFI is newer than latest on Apple site.

Currently charging battery.

This definitely looks like some hardware problem, but I'd like to know what.

I've installed Yosemite and now there are some changes.

When no externals are connected:

Instead of simple freezing, now it freezes and couple of seconds later turns off. But, it no longer runs fine via charger when battery is at 100%. Instead, it froze-shut off after 38 minutes. Then, I unhook it from charger and tried it off of battery, where it ran fine till it dropped to 77% after 58 minutes (of mostly torture, to speed up battery drain) and then it started randomly turning off. Every time I start it up again, it stays on for a shorter period of time, unless I let it sit off a bit. Then it "normalizes"

When FireWire HDD is connected:

Works flawlessly. Either battery or power adapter. Currently non stop working for over 15hrs without a hitch.


When it shutdown after first freeze in Yosemite, I've started digging up info on that and came to conclusion that SMC update should resolve it. So I tried it again and now SUCCESS. Also, I've never seen any update being done as fast as this. Preparing was typical (maybe around 30s), but actual update after restart, 1-2s max.

SMC firmware is now 2.2f44, but the problem persists.

I've reset SMC and PRAM again, but no change.

Noticed in Console "last shutdown cause" immediately after those random shutdowns: 5, 0 and finally -128. Although -128 is one when it started turning off quicker, both 5 and 0 coincide with freeze-shutdown. I've found that 5 and 0 are normal shutdown codes, but I don't see anything normal with what happened.

Also, I've noticed that computer fan is quite lazy. While stressing, GPU temp reached 90C, yet fan only slowly started speeding up reaching "blazing" speed of 2200rpm. I know fan works because it speeds up to full speed in ASD tests.

Now I decided to put ASD on internal HDD and boot it from there without any externals to see if any error appears. If it passes all tests (I've put it to do a loop of 3 passes in ASD OS), I'll do a bit of "transplanting", taking the logic board to a different case.

Will update with new info.

All suggestions are welcome.

Notice, there are no "apple geniuses" in my country, only guys with screwdrivers and soldering irons.

Ran ASD (ASD OS) from internal drive.
Selected all tests, just to see FAILED after 31 minutes. -33000 wrong drive type. Thought it might be something wrong with controller or SSD, so I went on a search to find what it is. Luckily it turned out that ASD expects HDD's on both SATA channels. Unchecked second channel (one where ODD is connected) and ran it again.
3 cycles on power adapter (battery at 99%) and 3 cycles on battery power (99% till 43%). Approximately 4hrs later (1.5h on power adapter, 1.5h on battery + 40-45mins first failed attempt on power adapter) PASSED.

Rebooted and now it plays music on battery power, no external devices. Uptime 20 minutes, battery at 39%. Waiting for freeze-shutdown, so definite "transplant surgery" can be scheduled.

EDIT: 10 mins later, freeze-shutdown. Last shutdown cause 3. Temperatures were normal (GPU sensor reported ~50C and ambient ~35C, although room temp is around 25C), computer was almost idle (playing music from Youtube in background).

Final update:
Currently it works a lot longer than before, but still freezes at the end (now lasts around 1.5h).

It happens without external devices, but also when you connect miniDisplayPort, USB or SD card (USB again). Currently don't have Thunderbolt cable to try if it's any different from mDP. (previous post stating that USB keeps it alive was wrong)

Only FireWire and ethernet keep this computer alive, and that's only if there is a device on the other end of the cable. It doesn't work if it's just cable plugged in, it has to have an actual connection established.
If it's FireWire disk, you can unmount it. If it's ethernet, it can be disabled in OSX.

Tried moving logic board to another case of an working cMBP (logicboard+speaker+magsafe module), same issues.

It something on a hardware level, that obviously uses some driver that doesn't report to Console, but can in effect block/turn off the whole computer.

I was thinking maybe about temperatures being a bit weird, but if it was because of overheating - why would it still work with FireWire and ethernet devices connected???

So the question is:

Does anyone know what happens on hardware and software level when you connect a device to FireWire or ethernet port?

There aren't any events in Console other than regular ones.

It may be cold/dry solder somewhere on the logic board, but where?