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Replaced Parts, Now Won't Power Up Except For Fans

Alright, this is for a late 2006 15" Macbook Pro A1211 / MA609LL. This is my fiancee's laptop so this makes the situation all the worse...

Needed to replace the fans on the computer, decided while I was in there I would also reapply some new thermal paste to the CPU / GPU / Northbridge because the computer has been running really hot for a long time, like 180 degrees hot (was running a temperature monitor to get an exact number). Now I'm a sys admin for a living, so I know my way around a computer and have built my own computers for over a decade. So please feel free to get technical, because my honor is on the line with my girl!

Ordered left and right fan, as well as battery connector cable from ifixit initially. Power adapter is only a year old, and I just replaced the battery (old battery wasn't holding a charge which is why I ordered the battery connector cable just in case). I followed the guides on iFixit

MacBook Pro 15" Core 2 Duo Model A1211

and took it apart down to the heat sink, put it back together and it wouldn't turn on. What I learned after careful review is that by not removing the left speaker over the left I/O board, before I installed the battery connector cable, I broke a pin. But I didn't realize this before connecting the power adapter back to the computer, and putting the battery back in and trying to turn on the computer numerous times, and putting the old battery connector cable back in thinking I might have gotten a defective cable - all to no avail.

So, now I order a left I/O board. It finally came today. My fiancee has been without a computer all week (my initial tear down occurred last weekend), using my laptop instead, but of course her data is on this thing. So, I carefully, very carefully, replace the Left I/O board, or the MagSafe DC Sound board with the ExpressCard slot. Apply new Kapton tape as I go. After I screw everything down, and I haven't yet put on the keyboard with the power button, I connect the power adapter to the MagSafe board, and the light does NOT turn on at all. I hope that that's because something still needs to be connected.

Now completely re-assembled, as soon as I put the battery in, the fans start spinning. This is BEFORE I've touched the power button. I hit the power button and nothing. I connect the power adapter to the new MagSafe DC Sound board and again, no light comes on, either green or amber. This is further than I got with the board that I broke the pin on, but still a far cry from even turning on. The only way to make the fans stop spinning is to physically remove the battery. It doesn't have a lot of life left as I write this, down to its last 20%.

I tried resetting SMC (held down power button for 5 sec w/o battery or power adapter connected), from what I've read, you can't reset the PRAM until you can get the #*&$ thing to turn on.

So, what is wrong? I was really careful, and definitely didn't break any pins on the motherboard with the CPU / GPU / Northbridge, it would just totally deflate me if I just blew her entire computer. I feel like not all hope is lost because the fans are spinning when power is coming from the battery, but the lack of a light on the power adapter is disconcerting. Did I get a bad left I/O board? I'm seriously pulling my hair out on this, and she is rightfully !^&&*^ off about the situation. Thank you in advance for any and all help!


seriously?! No answers in two days??? C'mon guys, help me out here!


As an aside, I also wanted to mention that the laptop is now literally 50 DEGREES COOLER after cleaning off the clusterf**k of a thermal paste job that apple originally did on the motherboard. I am now averaging temps between 129 and 134 degrees F! So, you know, do THAT...

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Have you tried dismantel and reasseble? Sometimes it's just a bad connection somewhere.

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EUREKA! I solved the problem, and I want to thank you jclark for giving me an idea that led to the solution! Although what you suggested about the GPU solders was not my problem, your explanation of how the light not coming on the charger meant that the motherboard wasn't completing a full circuit was the explanation I needed in order to find my way out of the forest of failure Heheh

In my quandry, I was scouring search engines and thus led to all sorts of websites for diagnosing all manner of Mac problems, and it frustrated me that so many people would come on various forums, ask for help, and then never update as to what ultimately happened with their machines. Oftentimes, some people would literally post 2 years later, "I'm having this same problem, what was the solution?" only to be greeted by the sound of proverbial crickets. Well, I don't want to be that person, so here's my solution and I hope it helps a lot of people:

It was the battery connector cable. I'm talking about this in case you're unclear:

[producto vinculado inexistente o deshabilitado: IF185-045-1]

I personally am not as cynical as jclark as to the quality of parts that one can find on eBay so I really didn't believe that I had bought a bad DC MagSafe Sound Board / Left Logic Board. Jclark's explanation of the completion of a circuit made me think about the battery connector cable, and how possibly this too could have been damaged as power was not flowing correctly since one pin wasn't connected. SOOOO, luckily I had bought anoter battery connector cable from iFixit BEFORE I even took the computer apart in order to rectify my battery charging issue (which wasn't the problem, just had a crap batter), so I swapped this out, replaced the thermal paste on the CPU/GPU/Northbridge (I used MX-4 btw, the best non-conductive thermal paste, and I used to be an Arctic Silver man all the way), and when I got to the keyboard I didn't screw it down, left the battery out, and connected the power adapter and VOILA! Success!@!

Also, in getting to this point, I broke out my multimeter and tested the power coming out of the power adapter in the interest of ruling out that I had damaged THAT in the process of connecting it to my old DC MagSafe Sound board / left logic board when I broke the pin and I want to just quickly share with you that I found the pinouts for the power adapter here:

and so, first I stuck the testing probes in the AC power cord unplugged from the DC converter, here luckily I also had a 60w power adapter (both are genuine Apple and not 3rd party chargers) that I KNEW worked from a friend so I actually had some basis for comparison. I measured 10.6 volts on my multimeter from both cords, so I knew that mine was still undamaged, but when I touched the probes to the MagSafe connector things became more ambiguous. Becaure while I was able to rather easily measure about 7 volts from pins 1&2 and 4&5 (for a total or 14 volts, under the 16.5 volts the 60w is rated for on the outside of the plastic transformer case), on MY 85w power adapter I was only to catch a 7 volt reading for a split second, and most of the time would measure about .75 volts from either pins 1&2 or 4&5. So really, I thought I had damaged the power adapter too.

Once I used the new battery connector cable internally to connect the DC MagSafe Sound board / left logic board to the main motherboard with the CPU/GPU/Northbridge, I tried the known good 60w power adapter to see whether a light would come on it, and it did, and once it booted all the way into OS X, I shut it down and connected my 85 watt power adapter and it worked too. So the readings I got from my multimeter that were really low apparently just caused me consternation unnecessarily. So, maybe someone who knows more about multimeters than I can contribute some knowledge as to why I got those funky low readings on my 85w power adapter when I got an easy 7 volts from either ground and positive pin pair on the MagSafe connector of the 60w power adapter, but I can't give a sufficiently scientific explanation myself.

So all in all, everything is cool except for one thing now - I can't adjust the brightness of the screen. The F1 and F2 keys don't do anything, and I googled this as well of course and there's supposed to be a brightness slider in the Display preference pane in System Preferences but there isn't on this laptop. The version of the OS is 10.4.11. Now that everything is working normally, my next project is to upgrade the OS onto a new HD, and this may solve the problem but I'd like to be able to make the screen brighter as it seems to only be as bright as when it initially dims after you haven't touched the screen for a few minutes. FWIW, the F9 and F10 keys to adjust the brightness of the back-lighting on the keyboard also don't do anything, however in that case, at least the big icon flashes on the screen and there's a tiny "no-smoking sign" underneath it, so that seems to be working more properly than the F1 and F2 keys, which when pressed do nothing whatsoever.

Thanks once again to jclark and I hope this helps somebody else! :)

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The most likely issue is the NVIDIA GPU solders have budged. The overheating is the most likely cause for this and it is a REALLY common issue with this model. When you took it apart, even just tilting the board upright would have caused this to occur (Gravity... TY Newton!)

There are a heap of guides on refluxing the solder online.


Once the GPU is under stress again it will break the solder and will need refluxing. Each reflux will reduce the strength of the solder until... It dies.

As for the issues you have experienced AFTER installing the Mag Safe Dc Board, the logic board is not completing a full circuit if the light on the charger is not coming on. I'd say you likely have a bad DC board (Ebay sucks :( ... ).

Try connecting the keyboard and then the power (No battery). Do you get a light? Will it turn on?

Macs work exactly the same as PC, the battery has 10-24 pins. It is the bridging of a certain 2-4 pins that cause the battery to open its other circuits, sending power to the logic board. If the logic board is powering on by itself, when battery is in, but wont power on at all once DC is in and battery is out, you have a serious fault. The pins (near the keyboard, often referred to as power pads) have been bridged. Try earthing these pins (you'll have to Google them as I don't have the P/N for your logic board) by holding a Flathead (make sure your body is contacting the metal of the screwdriver) to these pads and connecting the battery. If it doesn't turn on, voila! You have a faulty diode, located on the opposite side of the logic board, which will probably seem rather obvious as it will likely be a solder missing or something like that.

Its really easy to knock chips off near the heat sinks when removing them. I'd say that's the most likely cause of the new issue your experiencing.

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Very good +1

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