Computer only boots when cold, any suggestion?

I have a Core2Duo Mackbook pro that only boots when is at room temprature, after booting it works normally.

I've removed the logic board cleand it checked it for bad solderings but can't find a cause, maybe the soldering of the chipset or CPU.

Is there anyone with similar problems and if possible a solution (except replacing the card!).

Thanks

Answered! View the answer I have this problem too

Is this a good question?

Score 3

Comments:

Hey Miguel, does this problem occur when the laptop is plugged into AC power, battery power, or both? Have you tried to cold-boot it on AC power only (battery removed)?

by

The problem occurs always (battery or A/C) and when I reassembled the MBP I've replaced the thermal past.

As for the fans they are both running and even with the keyboard opened after 1 or 2 min running if I restart the MBP it dosen't boot and it dosen't seem to be hot enough to stop working.

by

Forgot to refer that I also tested it only with A/C and replaced the battery, memory, HDD and CD.

by

I'd say that there is a probably a crack in one of the boards (logic/left I/O) that expands and contracts when it heats and cools. Could also be a solder joint that's doing the same thing.

by

I have the same opinion as mjuergens.

thanks everybody

by

Add a comment

9 Answers

Chosen Solution

I agree with Sterling, if you removed the logic board and didn't use new paste (and clean the old off first) you could see this problem.

How about a bit more detail.

You say it has to be room temp to boot, when not at room temp describe what you mean when you say "wont boot" - no chime, grey/blue screen o'death?

After it boots it then runs ok - for how long?

Does the fan kick in?

What OS are you running?

Might be board flexing under heat so that something in the post is not making contact, but once it passes post the problem will not cause a shut down.

Was this answer helpful?

Score 2
Add a comment
Most Helpful Answer

I would check the thermal paste on your CPU. If there is a heat sink that came loose, it could cause overheating problems.

Was this answer helpful?

Score 3
Add a comment

Have you run something like iStat Pro to monitor fan speeds and reported system temperatures?

Does your MBP shut off after a period of time?

Was this answer helpful?

Score 2
Add a comment

The problem is probably your temperature sensors. If i was you i would buy a fan or a fridge :) and keep it on it while being used. Maybe you could turn it a permeant desktop.

Was this answer helpful?

Score 1
Add a comment

"The screen is completly black no chime and the power led fade in and out."

This is an indication the unit is 'sleeping'. Check the area around the sleep led - something might be triggering the sleep sensor inadvertently. On your model, it is part of the ribbon cable connecting the hard drive to the logic board - you might also want to check it for damage, debris, and proper routing.

Was this answer helpful?

Score 1
Add a comment

maybe your temperature sensors are broken? If they are set too high perhaps it wouldn't turn on at higher temperatures because it thinks it's too hot to operate?

Was this answer helpful?

Score 0
Add a comment

I've cleaned the old and used a new paste.

When it boots it works normaly until I power it off.

The fans start normaly.

The screen is completly black no chime and the power led fade in and out.

AS for the OS I don't think is relevant at this boot level but is Leopard with all the updates, sorry can't remember the version.

I think that is somthing related with soldering that expands with the heat and stops making contact.

As for a problem with the sensor, it could be but I think it would't work hours without shuting down.

In the original state it only booted twice in 3 months...

Then a friend told me to try a heat gun.

So we did it very carfuly for keeping the components in place and using a screw driver to apply a small pressure.

First we did it in the CPU and after in the chipset, and now is in this state that is far better, it boots every day as long as is cold!

Was this answer helpful?

Score 0
Add a comment

I'd say that there is a probably a crack in one of the boards (logic/left I/O) that expands and contracts when it heats and cools. Could also be a solder joint that's doing the same thing.

Was this answer helpful?

Score 0
Add a comment

Sounds like a bad solder joint, if you want to risk it, use a heat gun, and go all over the logic board, around the CPU\GPU especially, this will essentially remelt the solder, and reform the joint, this is basicly what causes the "Red Ring of Death" in Xbox-360's, and can be corrected either tepmorarilly, or permenently by this fix.

Note: this fix is risky, and you run the risk of damaging components if you keep the heat gun on the chips too long!

Was this answer helpful?

Score 0
Add a comment

Add your answer

miguelb will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 4

Past 30 Days: 12

All Time: 4,408