SMC issues after liquid spill, MBP 13-inch mid-2012

[Marcool]

Hi all,
I have a "MacBook Pro (13-inch, Mid 2012)", which has had coffee spilled over its keyboard and air-vent. As soon as that happened, I shut it down, opened it up and unplugged the battery. Took it all to pieces as much as possible, dabbed up all the liquid I could see, then left the machine in pieces and all components inside a sealed bag with a load of rice for about 72 hours.
Now, having assembled everything again:
-> the power button doesn't work (can't turn the machine on).
However, when I disconnect the battery, then reconnect it, a few seconds later, the laptop does power up, with:
-> fan spinning at full speed.
-> battery indicator "crossed-out" and says no battery is present.
-> iStat and System Profile also report no battery.
-> iStat sees no temperature sensors either.
All that sounds "SMC" related to me. I have attempted a SMC reset, to no effect. I have an identical battery which I tried in and observed no change. I have tried disconnecting the battery and holding the power button for a long time, no effect. I have inspected the logic-board for any rust, corrosion, liquid and cleaned with alcohol anything I thought looked suspicious.
I'm at a loss here. I wonder if anything can still be done or if some component in the SMC is dead. I'd love to have some help if anybody has any more troubleshooting steps I can try.
The picture shows the logic board.
EMC No.: 2419
MLB NO.: C02132700AWDRKQA4
Thanks in advance.
Best regards.
Mark.

PS: I have had a cursory look at this thread https://forums.macrumors.com/threads/smc-issue-on-mbp-13-hardware-troubleshooting-guide.1122338/ but I can't get the laptop to power up with the "trick" indicated there in the first post, that uses the magsafe, and it is not quite the same model so I'm not sure how much help the information there should be anyway. The pictures of the logic board clearly don't match up with mine.

 

[wubsylol]

My understanding, based on having the same thing happen to my 2011 15" MBP a few years back, is that the logic board has short circuit protection and will prevent the battery and elements of the SMC from functioning if it detects a short. Eventually, mine just came good. You might just need to wait a bit longer, fine spots of moisture might remain causing a short somewhere on the board.

 

[DeltaMac]

If so, "Fine spots of moisture" remaining can just as easily continue to corrode, causing further damage.
This can actually take a few days (even a few weeks) to continue to deteriorate.
Unfortunately, you already have problems which, in a few reports, might recover if left off for a few days (or weeks), but, in my experience (as a service shop tech), your situation will not get better until you replace the logic board.

 

[DarkSel]

I would get the logic board professionally cleaned.

FYI putting your components in rice is not a good idea. When rice gets wet, it will residues.

See here for some other steps you should follow, including drenching your board in isopropyl alcohol: https://www.ifixit.com/Wiki/Electronics_Water_Damage

 

[Audit13]

There may be capacitors and sensors on the logic that need to be replaced.

I recommend removing it from the rice, remove the motherboard, clean any affect areas with pure isopropyl alcohol, let it air dry, and try it again. If the fan is still spinning on high speed, it's time to have the logic board repaired or replaced.

 

[Marcool]

I would get the logic board professionally cleaned.

FYI putting your components in rice is not a good idea. When rice gets wet, it will residues.

See here for some other steps you should follow, including drenching your board in isopropyl alcohol: https://www.ifixit.com/Wiki/Electronics_Water_Damage

Thanks for the advice DarkSel, but I didn't put the computer in rice it put it in a sealed bag, with rice in the bag, but not touching the components directly. I.e.:no rice has gotten into the machine at all (and I've already removed it from the bag anyway).
I had read the ifixit page about water damage. I guess the only problem I had with the isopropyl alcohol was that it runs the risk of dissolving the thermal paste under the CPU heatsink, unless I'm very mistaken? I suppose re-applying heatsink paste isn't that much of an issue but it discouraged me to learn that was a possible effect of the isopropyl alcohol.

There may be capacitors and sensors on the logic that need to be replaced.

I recommend removing it from the rice, remove the motherboard, clean any affect areas with pure isopropyl alcohol, let it air dry, and try it again. If the fan is still spinning on high speed, it's time to have the logic board repaired or replaced.

Audit13 thanks to you also for your advice. As I mentioned, it is out of the rice. I like the approach of cleaning it with isopropyl alcohol, rather than submerging it as iFixit recommends, that's for sure.
Audit13 and DeltaMac: I think if the logic board does needs replacing, then I'll just purchase the same laptop, and keep parts from this one as "last-resort" spares, since the cost of a "used" MBP mid-2012 is barely more than that of the logic board at this time…

wubsysol: that's interesting to hear. I must say, it is not my natural inclination to be optimistic at this point, but as you say, maybe some time (after a more thorough cleaning to account for other comments wisdom), I might get lucky after all!

I'm happy for advice if anybody can advise on how to use the isopropyl alcohol best. What do you do about dust that's on the board, I would imagine that will sort of "cake" when humidified won't it? Need air-blowing off first? I'm not sure who around my place would do "professional cleaning" for computer parts :/

 

[Dadioh]

The issue here is most likely residue from the liquid spill under the SMC. The SMC is the square package along the edge of the board halfway between the fan and the video connector. Since it is right beside the hinge/air intake area it often gets the liquid directly which seeps under the SMC and can cause shorts and also solder ball corrosion. Putting the board in a desiccant evaporates the water but leaves behind everything that was dissolved in the water. Side note... rice is not a great desiccant to use. Silica beads are much much better than rice and you get them for free as little desiccant packets shipped inside many products. Put the silica bead packets in a zip lock bag along with the liquid damaged circuit board.

So the issue now is to get the contaminants under the SMC dissolved and cleared out of there. The best way is with an ultrasonic bath which many repair shops should have in their inventory. Lacking that the next best method is to use Isopropyl alcohol and water. The alcohol acts as a wetting agent to reduce surface tension of the water allowing it to seep under the SMC. The water does the heavy lifting of actually re-dissolving the contaminants. The issue is getting the resulting solution out from under the SMC (which is what the ultrasonic bath does so well). You can simulate the action by using a toothbrush (new.. not something you have had in your mouth) to vigorously scrub the top and sides of the SMC trying to create pressure to force the solution under and through the bottom of the SMC (solder balls). Apply the IPA/water solution just to the SMC area and any other area that looks like it has residue. Allow to dry for at least 30 minutes before reassembling and powering. If the board is out of the chassis you could use a hair blow dryer on low setting to accelerate the drying process.

Having said all of that, this only addresses the leakage currents due to the contaminants. If corrosion of the solder balls has taken place then no amount of cleaning will reverse that.

You probably also need to replace the keyboard. The power switch is integral to the keyboard assembly and non-functioning power switch is a common side effect of liquid spill.

 

[Audit13]

A cheaper solution that repairing the board may be to buy a used mid-2012 13" MBP with a busted screen and use those parts to repair your MBP.

BTW, the logic board from an early 2011 13" MBP will fit inside a mid-2012 13" MBP. I know because I did this with my nephew's 13" MBP. He lost USB 3.0 but gained a fully functional MBP.