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Lanzado en octubre de 2008 / 2.4, 2.53, 2.66, 2.8 o 2.93 GHz Procesador Core 2 Duo

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Computer boots up ONLY when chilled to <60° F.

This computer was in storage for months because it will only sporadically start up at room temperature when pressing the power button. The issue is definitely temperature-related. It went to the Genius Bar a couple of years ago for the exact same issue. They "fixed" it by replacing the motherboard, costing us >$300. The genius explained to us that the model was too old and they would not fix it for us again. That fix lasted a couple-three months before the issue returned.

The issue: Computer off. Press power button. Power LED comes on, but no chime and the screen doesn't light up. This is an intermittent failure, on rare occasions, the computer actually did start up, but most often it did not. It was completely unreliable.

Attempted fixes: Reset NVRAM, failed. Reset SMC, failed.

Once, when it did start for me, I took the opportunity to upgrade its system software from Snow Leopard (10.6) to the latest it could run, El Capitan (10.11). When attempting to restart to install the new system, of course the computer again failed to chime and the display failed to light up. After repeated tries, it went into storage.

Getting close to the holidays now, I decided to take it into a local Mac shop to see what they could do to it. I put it into the car parked in our unheated garage so I would not forget to take it with me when I left. It was ~55°F in the garage, and MBP sat in the car for a couple hours before I left.

When I got to the repair shop, after checking the battery state, the tech immediately pressed the power button… CHIME!, display came on and the computer booted right up. He looked at me, "I guess I just have the magic touch" he said.

I left it on and took it back home. As soon as I arrived home, many other issues became apparent: no keyboard backlight. Both fans running at top speed (6,000 RPM) constantly without loading the processor. Apps taking forever to open. All signs of NVRAM needing a reset. By that time, the computer had warmed up to our ambient temperature, a little over 72°F. Intending to do another NVRAM reset, I clicked "Restart", the computer shut down and bingo, right back to the original issues.

But now I had something new to try— putting it back out in the garage. I force-shut it down, and took it out to the garage and left it there. Couple of hours later, I went out and pressed the power button. Chime and the computer started right up again. Finally, after repeated tries, I managed to reset both the NVRAM and the SMC, so everything runs fine (keyboard backlight works, fans running at or near the target rate ~1,900 RPM).

Except when I try to start the machine inside our house. Then, it goes right back to the original issue: power light, no chime, no display. But all I have to do to restart it is leave it in the garage. This is easily and totally replicable, and the only only dramatically different change between the garage and our living room is the ambient temperature (well, and there is no car parked in our living room).

I haven't tried refrigerating the Mac… yet. Thanksgiving leftovers, y'know. But I bet it would work if I did.

Here are some of the causes I have been cogitating on (in no particular order):

1. The hard drive (it's the stock OEM HDD, 200 GB, probably 5400 RPM). I know sometimes HDDs can be brought back to life by putting them in the freezer, but I can't see hard drive issues adversely affecting the display.

2. Maybe a poor connection between the motherboard and the display? But why would that keep the computer from finding a system and chiming?

3. One or more of the internal temperature sensors (although it seems a malfunction there would adversely affect the machine AFTER it's started up).

At this point, I can't even tell if it's running a POST when I turn it on.

If you managed to read this far, holy crap— you're amazing. (And parenthetically, it might be time to get a life. You know, just sayin'.) And if you have a similar issue, absolutely try cooling it off very thoroughly to about 55°F and see if it works for you. And anyone who wants to chime in (see what I did there?) with suggestions about the cause, know that I am genuflecting to you not just because of your awesome knowledge, but also the fact that you would share it with someone of my humble stature.

Thank you SO much!

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You could always bring it out in the garage and run a Apple Hardware Test Write down any error codes because I know they definitely check the temp sensors in the test... <----- Here is a link to download the AHT just find your model download it and use disk utility to create a bootable usb from it and boot from usb to run test


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I'm hoping that I don't have to download the AHT. Maybe it was included when I upgraded to El Cap. Anyway, you are the second person that recommended to me to see what AHT had to say, so I'm cooling it off in the garage right now. I'll update.

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Well fixing' macs is my life, so I have kind of one. In certain circles I am considered a Mac god so the genuflection is meet and right so to do, but in your case not required as we may have to try a couple of things.

But lift up your heart as you have humbly approached the throne of Mac knowledge in a manner to warrant our best efforts. Let us not he fascinated by these earthly and corruptible elements which we see with our eyes and touch with our hands, but rather just try to get them to work.

The first thing I would do on this model is replace the thermal paste. Also when removing the heat sink observe the logic board and look for an oily residue, If you do find it stop, and let us know. Here's how to do the thermal paste:

MacBook Pro 15" Unibody Late 2008 and Early 2009 Heat Sink Replacement

Cómo aplicar pasta térmica

Imagen de Electronics Skills


Cómo aplicar pasta térmica



5 - 20 minutes

Imagen de MacBook Pro 15" Unibody Late 2008 and Early 2009 Heat Sink


MacBook Pro 15" Unibody Late 2008 and Early 2009 Heat Sink Replacement



1 - 2 hours

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I used to have a great deal of confidence working with tiny screws and components. But since I've developed arthritis (where once all I had was simple carpal tunnel syndrome), if it is the thermal paste I'm probably going to have to take it in. Let younger fingers deal with it.

BUT! Your links were both fascinating and instructive. Thanks!

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@allseasonradial believe me I understand. I'm getting my Piroxicam in Mexico after they raised the price from $4.00 per month to $400 a month.

Take a close look at that logic board. The heat sink on this model is prone to leaking (it is liquid filled). That is what that residue may be and will cause your symptoms. It's a cheap part but very difficult to diagnose. You won't find this solution in the books, only years of experience and not quitting on problems allowed me to discover it on my granddaughters machine. That residue was the key. Since then I have seen it several times, but you have to know what to look for.

The liturgy comes from also being as pastor when I'm not fixing them or helping others to fix them.

We seldom get such well phrased questions and I appreciate it when I see one. It makes this fun.

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I have carpal, tendonitis and my fingers are getting worse and worse. As I get old and my pain gets worse, I find that good tools and proper form make it so I can still do OK. I also find that I feel much better after I succeed in a job I wasn't sure I would be able to do. I also found that hitting my physical limit helps me understand my body and is not a bad thing.

OP, give it a try. Update this and tag me if you can't get it done. This is a pretty unique problem and i would thoroughly enjoy fixing it if you aren't able. No charge of course.

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@joshw how old are you? Sounds like a senior citizen like @mayer and myself :-) Anyhow, holler if you need the schematics for this computer. My concern here is a bad chip design or cold solder issue. maybe a reflow....:-)?

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I'm 38. But I'm an old 38.

I think the heat sink is where I would start, then go on from there. Something is overheating, I just have no clue what.

I won't lie... The idea of sticking a computer in the freezer as part of a repair makes me really excited.

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I'll offer that the cold may affect the battery, wiring, and friction-fit metal connections/terminals.

Metal expands and contracts proportionately to it's temperature state(s), which may affect the contact points of wiring harnesses and connectors. Albeit perhaps a very fractional difference, this might be part of your issue.

Additionally, increasing heat within an electrical system incurs a corresponding increase in the electrical resistance of the system. Conversely, decreasing the temperature will decrease the resistance.

Perhaps your decrease in temperature allowed an otherwise failing battery to sustain the necessary amperage for start/boot-up, due to a decrease in system resistance…?

…could also be thermal sensor related, keeping extra cold will obviously prevent overheat-protection from being engaged. Decayed thermal paste is likely, and unless you have a verified functional spare battery available, this would be primetime to investigate the heatsink and any / all physical connections.

Good luck.

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Keith Keber estará eternamente agradecido.
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