I got a dirty mac - Page 1
Forum section: electronics / repair

author: Shock
author_rank: Super Contributor
timestamp: July 17, 2015, 04:54:18 am
content: Here is an Apple Macbook Pro I'm repairing, it was left in a damp place and I received it about a month after it had sustained some pretty convincing water damage.The symptom as received is no boot, no lights, dead. I decided there is no advantage turning it on and instead went straight to inspecting the PCB (or what Apple calls Logic Board).I found plenty heavy metals corrosion set in around the PCB and my initial concern was it could be quite time consuming and a pain in the ass if I have lost traces and vias.Next I disconnected everything and removed the logic board, it's easy to damage these small cables if they aren't removed carefully. I took some sloppy photos of how the cables were routed and twisted to make reassembling easier. You need micro phillips and torx screwdrivers for this specific model.After the logic board was out I removed the speaker and heat pipe/sink assembly which both come attached to the logic board. Primarily if I needed to bathe the board or use an ultrasonic bath. There are also a few foam pads holding the speaker in place and one in the middle of the corrosion which looks placed to prevent shorting or impact damage.There was way too much thermal compound applied to the cpu and heatsink, probably about triple what is required for a good thermal bond. The compound was all through the components on top of the cpu, really messy.Here is the water damage, it's pretty much the same around 3 edges of the board. I took photos before I started to pinpoint problem areas for testing later, they are disgusting.

author: Shock
author_rank: Super Contributor
timestamp: July 17, 2015, 05:23:00 am
content: The CPU (on the other side of the board) took about 10 minutes and a pile of cotton buds to clean the compound away with alcohol, it was dry and nasty. I had to gently roll them until they took up as much of the sludge as possible before using the next, you want to totally avoid getting that on to the PCB and under the CPU. Residue always shows up later so I gave it a couple of more wipes with fresh alcohol.Back to the main problem and after two good rounds of 100% IPA and a soft bristled brush pre-soaking and then slowly working back the corrosion crap this is what it looks like. I've done another two problem spots and removed the foam pad residue (upper left). Don't ask me how long this all took, too long.I've attached the fan, power connector and power supply and booted it briefly (no heat sink yet), and guess what? The dirty mac has awoken!To be continued...

author: wraper
author_rank: Unknown
timestamp: July 17, 2015, 07:39:41 am
content: IMO it is not repairable. You'll need to wash it in ultrasonic bath, remove many QFN packages. But from the experience I'm pretty sure this board have damaged tracks and vias, so trying to repair it will be waste of time.

author: wraper
author_rank: Unknown
timestamp: July 17, 2015, 07:46:31 am
content: BTW cleaning corrosion with IPA is wrong as the idea. Trying to dissolve salts with organic solvent.

author: Psi
author_rank: Super Contributor
timestamp: July 17, 2015, 07:54:07 am
content: She's dead Jim

author: helius
author_rank: Super Contributor
timestamp: July 17, 2015, 07:59:31 am
content: I found IPA to be middling to poor at removing thermal paste. Straight heptane works a lot better.

author: jwm_
author_rank: Frequent Contributor
timestamp: July 17, 2015, 08:02:59 am
content: Excellent work repairing it. Looks like newI will do several washes (not soaks) in distilled water to dissolve and wash off salts or whatever water soluable stuff was brought in on the initial water damage, then a final scrubbing with IPA to displace the water (and whatever it dissolved). Not sure why people think it is a lost cause, water damage to electronics is pretty horrible looking but generally not too bad to repair, whatever the water brought in, distilled water will re-absorb and wash out.

author: wraper
author_rank: Unknown
timestamp: July 17, 2015, 08:14:55 am
content: Quote from: jwm_ on July 17, 2015, 08:02:59 amDistilled water won't do the job to remove the corrosion. Some chemical dissolved in the water and ultrasonic bath is needed to remove the corrosion/salts from underside of the parts. But that's not enough. On such boards with small tracks and tiny parts, corrosion completely destroys solder joints, often together with the pads on the part and PCB. But this is not so huge issue unless under BGA. The worst is damaged vias. I don't think you ever repaired something of similar complexity with serious water damage.

author: Shock
author_rank: Super Contributor
timestamp: July 17, 2015, 11:03:46 am
content: Thanks for the advice, my reasoning for the IPA initially is I wanted to avoid water soak under the ICs. I may yet use distilled water, but at this stage I needed to halt the majority of the corrosion and see whats underneath, prevent shorts, test operation and deduce how complex further repair maybe.I forgot to mention this is pro bono for someone I've decided to help out. The quote for the job was $600-$700 USD from repairers which were writing off the board, so this is an uneconomical repair which ever way you look at it. The value of the macbook with accessories in perfect working condition is about the same.As I mentioned in my second post it now boots. I'm not out of the woods yet but it is looking promising. I can do component level and trace/via repair as well (why not since I've already gone this far lol). There are definitely a couple of pads that need cleaning.In order for the repair to be as good as I can get it, to last a few years, yep I need to ultrasonically clean it.Major problemI don't have access to a suitable ultrasonic bath nor have I heard of anywhere here who actually offers this service for electronics repair. If you want a ring or a gearbox cleaned though no problem!So if anyone reading this is in SE Queensland, Australia and has a Crest or similar with a 5L tank with distilled/detergent setup please let me know.Coming up next I have to find where I put my thermal compound. Then I can clean the connector cables reattach the heat sink and check if peripherals (keyboard, trackpad, display etc) are operational.

author: wraper
author_rank: Unknown
timestamp: July 17, 2015, 06:17:10 pm
content: Quote from: Shock on July 17, 2015, 11:03:46 amMay I ask, how are you going to repair vias which are eaten away by corrosion? This is not 2 layer PCB after all and most likely have blind vias too.QuoteToo PITA for pro bono

author: Kleinstein
author_rank: Super Contributor
timestamp: July 17, 2015, 08:00:05 pm
content: Corrosion / water damage looks quite bad, but you still could be lucky that no serious damage has occurred.The first step would be just cleanng under plenty of normal water maybe with some detergent - then disstilled/deionized water and than maybe IPA or compresed air.Give it a try, but expect the worst. Further repairs a likly not economical.

author: Shock
author_rank: Super Contributor
timestamp: July 17, 2015, 08:53:13 pm
content: Quote from: wraper on July 17, 2015, 06:17:10 pmBlind vias present a problem. I'm not at that stage yet, I would like to get it ultrasonically cleaned. I've had a close look and it's not all that scarey anymore. Perhaps I'll have to ask around in advance who has a xray machine running and mine some small holes.Quote from: Kleinstein on July 17, 2015, 08:00:05 pmYeah I don't think I'll be using tap water or random detergents at this stage, but I'm looking to get it cleaner.

author: jwm_
author_rank: Frequent Contributor
timestamp: July 18, 2015, 12:57:02 am
content: Quote from: wraper on July 17, 2015, 08:14:55 amPerhaps I've been lucky, but corrosion is often just skin deep. I agree that totally destroyed vias or traces under bgas and you are pretty much SOL, but, a simple cleaning does work in enough cases that its worth trying.

author: daybyter
author_rank: Frequent Contributor
timestamp: July 18, 2015, 01:21:57 am
content: Australia? Lemon64 has many users from there and they repair old computers. Ask there for help.

author: jlmoon
author_rank: Unknown
timestamp: July 21, 2015, 09:01:26 pm
content: Quote from: wraper on July 17, 2015, 06:17:10 pmI sure wouldn't want to rely on this one for mission critical operations. Corrosion means material state change or loss of original compound, there simply isn't any way to ever get the original compound back.

author: Shock
author_rank: Super Contributor
timestamp: July 22, 2015, 03:46:09 pm
content: Quote from: jlmoon on July 21, 2015, 09:01:26 pmI threw that copper sulfate with the 100ml or so of alcohol I used to wash the PCB out on the grass, I'm into green/blue recycling.

author: Shock
author_rank: Super Contributor
timestamp: August 14, 2015, 06:22:35 am
content: Got another repair out of the way so had more time to finish a little more on the dirty mac.I'm disappointed I could not get hold of an decent ultrasonic cleaner, I think it would make the difference between it running for months vs years. I did wait to see if additional corrosion came up and nothings noticeable so far.Found the thermal compound and put the CPU heatsink pipe assembly back in and cleaned all the connectors, they had more of the same blue/white corrosion. Tested the battery charging circuit, seems to be working fine, battery is holding and gaining charge. Disconnect the battery before plugging in the display connector, it can easily blow the backlight fuse otherwise.Lastly hooked up the power while it's still in an upside down position and the fan hit 100% and it appears the CPU is certainly doing something. Still looking promising as you can see in the cryptic photo....

author: Ketturi
author_rank: Regular Contributor
timestamp: August 14, 2015, 02:22:54 pm
content: I'm writing this with same model macbook pro that had very similar water damage from beer bath. Logic board was completely dead. I used soapy water to rinse all water soluble stuff out with nylon brush, then rinse with clean water (water is actually really good solvent, just use deionized water). After that I put whole logic board in brake cleaner bath (mixture of different long hydrocarbons), to drive out all water and dissolve any oils and crude that water didn't get. After that just left it outside in sun to dry up. After that macbook booted, but one memory slot was not working, so bit more brake cleaning stuff, and it came back to life. Keyboard was toasted, but $30 replacement from ebay worked just fine (I could not get keyboard back-light to work due different connectors).

author: helius
author_rank: Super Contributor
timestamp: August 14, 2015, 04:09:11 pm
content: I have had various notebooks with keyboard backlighting for 10 years and never used it once.@Shock: I think I need to ultrasonic clean the touchpad assembly in the one I use. I will have to acquire a cleaning unit, but I think I know what solvent to use: Branson EC, which is advertised as not leaving any conductive residue.

author: G7PSK
author_rank: Super Contributor
timestamp: August 14, 2015, 05:40:19 pm
content: Have you looked at Louis Rossmann's videos on you tube, he shows you how to repair Apple logic boards including tracks and vias.

author: Shock
author_rank: Super Contributor
timestamp: August 15, 2015, 04:51:41 pm
content: Quote from: Ketturi on August 14, 2015, 02:22:54 pmI've not looked into break cleaner for this purpose, would it depend on brand as well? What is it made up from? Does it have any downsides in using it?I have similar hesitations with trying something new as with acetone and plastic solvency. Limited exposure limits the damage, but still I would want to know any downsides or long lasting effects ahead of time. I do like the idea of soft abrasive loosening of the contaminants though, ultrasonic is the only thing better after that for me, flooding the area with the "solvent" takes care of static issues.Obviously there are a lot of old wives remedies for electronics cleaning but I'm down for anything that has strong science behind it.

author: crerus75
author_rank: Contributor
timestamp: August 15, 2015, 06:08:16 pm
content: Generic non-chlorinated brake cleaner is usually a mixture of acetone, toluene, and methanol. Looking at the MSDS for a few different types seems to confirm that these 3 ingredients are pretty common to most of them. The MSDS also hints at ranges of proportions but doesn't give exact ratios for proprietary reasons.I have mixed my own in the past from ingredients purchased at the local hardware store. Each of the three listed chemicals costs around $12-15 (USD) in gallon quantities. Aerosol cans of brake cleaner are usually around $2-3 (USD) per can, but much of that is propellant, and though I haven't done the math, I suspect that purchasing in quantity and mixing my own saves me a bit of coin.I mix in proportions of 50% acetone, 25% toluene (or xylene if toluene is not available), and 25% denatured alcohol (AKA methylated spirits, AKA ethanol with methanol added to make it undrinkable). If you want true methanol, it is often sold for a few dollars a gallon at places that cater to race cars and at some hobby shops. I've found methylated spirits to work fine, but I've also never washed circuit boards with my witches' brew. You can also find true toluene at some hardware stores (at least here in the States), but xylene seems to be more widely available in my area.Acetone can be very aggressive on some plastics, as can xylene or toluene. ABS, polycarbonates, PVC, and a few others will dissolve in acetone, xylene, and/or toluene.

author: Shock
author_rank: Super Contributor
timestamp: August 15, 2015, 07:45:10 pm
content: To my knowledge both pure Ethanol and IPA are effectively residue free, are they interchangeable ingredients in break cleaner mix? Since I don't need a lot it's a bit more convenient for me to use IPA instead, I'm guessing Ethanol would be cheaper.

author: Shock
author_rank: Super Contributor
timestamp: August 15, 2015, 09:09:39 pm
content: Quote from: G7PSK on August 14, 2015, 05:40:19 pmI watched some videos, He works like a clumsy ape and I don't see the point in his continual repetitive nut job banter, the only thing interesting for me is the repair process itself. For people with a broken Macbook that the cat pissed on He may well be their go to guy, most laptop repairers are truly horrible at component level repair, which is where He seems to get additional work from.Battery fully charges, I need to put this back together.

author: Ketturi
author_rank: Regular Contributor
timestamp: August 16, 2015, 12:27:41 am
content: Quote from: Shock on August 15, 2015, 04:51:41 pmYup, brand does affect. I buy one from Biltema, Nordic hardware store, which contains by looking MSDS Hydrocarbons C6-C7 (hexane and heptane) ~65% and butane/propane and tiny bit of hydrocarbons C9-C11, so no acetone in this one. Acetone could eat some plastics, but I have used it too as PCB cleaner and never had problems with IC packages. Some connectors tho could be damaged.Windshield washer fluid could also work, have sometimes used it with some success. Those are kinda ghetto means, but hey, they have worked for me and when real electronics and contact cleaning sprays cost >3 times more (and often contain some mineral oil that just messes everything) I'm willing to take risk with otherwise zero cost projects.

author: crerus75
author_rank: Contributor
timestamp: August 16, 2015, 02:32:34 pm
content: Replying to a couple of different posts at once:Yes, there's a danger that acetone and toluene/xylene will dissolve some plastics, but as Ketturi says, the plastic packages on most board components seem to be resilient. Individual results, as they say, will vary.Windshield washer fluid is often a mix of water and methanol, so it will have some cleaning ability. In my opinion, it's not ghetto if it works-- just clever. I would still prefer to buy straight methanol or methanol/ethanol at the hardware store, but that's because I have one close by and the chemicals are readily available.Some of the traditional contact cleaners have been reformulated, banned, or increased in price due to regulations on the ingredients that make them up. Luckily, methanol/ethanol/IPA are still inexpensive and readily available (at least here), and they're usually sufficient for washing down circuit boards.If you want to use something more aggressive, I would try a commercial aerosol brake cleaner first. If there's an MSDS for it (there will be if it's sold in the US, not sure about international regulations), read it first to see (approximately) what's in it. Non-chlorinated ones tend to be a flammable mixture of hydrocarbons of some type. Chlorinated ones (non-flammable, usually) are something else entirely. A quick scan of an MSDS states that tetrachloroethylene and/or perchloroethylene are the ingredients in the chlorinated ones. I have no idea about their composition or compatibility with plastics or their suitability as a contact/circuit board cleaner. I tend to use the non-chlorinated variety out of personal preference. The only reason I mix my own is because I tend to do a lot of mechanical work and when I do I go through a lot of brake cleaner. It makes sense for me to buy in bulk, but maybe not for you.Having said all that, whatever type of alcohol (methanol, ethanol, or IPA) you have available to you should remove most of the contamination with little to no residue. Only use something more aggressive if you really need to.

author: Stonent
author_rank: Super Contributor
timestamp: August 17, 2015, 03:08:59 pm
content: In the US I've frequently seen denatured alcohol containing benzene as the denaturant. Bittrex is also frequently added to further deter from trying to drink it.

author: Shock
author_rank: Super Contributor
timestamp: November 24, 2015, 09:14:52 am
content: Just an update...I ended up cleaning it in two rounds the second I went across it again completely and gently worked the problem areas. I flooded the board as I went with IPA washing off contamination to the side. Couldn't see any visible corrosion after letting it sit around a few months, even under magnification.The dirty mac is now back in it's owners hands. Seems to work well, beeps, tells you the time etc.Fixed!

author: Stonent
author_rank: Super Contributor
timestamp: November 26, 2015, 01:36:34 am
content: Quote from: Shock on November 24, 2015, 09:14:52 amSomething I'd like to add to this was something I saw in a recent Applied Science video. Pure alcohol is not always as good of a solvent as a dilute mixture. He showed cleaning a dirty slide with pure IPA vs 70% and the pure IPA got rid of some of the residue but not all. The 70% cleaned all of it off because I think it was dirt does not dissolve in IPA but does in water. So the mixture could clean everything.

author: helius
author_rank: Super Contributor
timestamp: November 26, 2015, 01:34:34 pm
content: 70% IPA leaves a lot of residues, primarily because some water is left behind after evaporating the alcohol. 91% dries quicker and more evenly and makes a better solvent. Very little flux residue is salt: only fraction of a percent of halides to increase activity. If boards have been extensively handled there may be more salt from sweat on them.

author: briselec
author_rank: Regular Contributor
timestamp: November 26, 2015, 08:51:40 pm
content: Quote from: Shock on August 15, 2015, 04:51:41 pmdownsides? That would be a BIG yes. Under certain conditions it can result in a painful death. Another side effect is nerve damage. Google the dangers of brake cleaner. Personally I wouldn't even consider using it.

author: Shock
author_rank: Super Contributor
timestamp: November 26, 2015, 11:29:11 pm
content: I used 100% pure IPA in a spray bottle, it looked like it needed scrubbing so most of the work was with the soft bristled brush (very gently) when it was saturated with IPA, more as a rinsing action and to prevent static build up rather than dissolve. In this case it worked very well by itself.The contamination ended up a soft sludge in the bottom of the container I was holding the PCB over.