Solved Laptop won't start after cleaning and applying new thermal paste

[OverEight]

Hi, Recently I decided to clean out my Toshiba Satellite Pro laptop, given that it just so dusty it was constantly overheating. I spent an ardious 3 hours to remove all of the factory sealed screws by hand, then I dusted out the CPU fan with an air spray can, and finally applied new thermal paste. After assembling it back together, I come to find that it will no longer turn on! When I try to charge it, the lights on the front pulse for a second, then cut off, then pulse etc. If I had to guess I would say this is a CPU or PSU problem, and perhaps I failed to assemble the CPU back together properly? I was also grounded the whole time. I'm almost certain everything is back in place, including the wires. Any help would be appreciated. EDIT: There is also a clicking noise coming from the PSU.

 

[Megahertz07]

Did you try to run it without the battery or only on battery? Is the clicking noise coming from the external PSU?

 

[OverEight]

With the battery. Oh, and when I said the clicking noise was coming from the PSU, I was mistaken, it was actually comming from the DVD drive, which is one of the first components to start up on my laptop. I've taken it apart again and to tell you the truth I can't see what I've done wrong. There's a chance some static reached the CPU, thereby damaging it, but I still doubt it. At worst, I may have accidentally detached the heatsink from the CPU, but I fitted it back on perfectly just after.

 

[OverEight]

Anyone?

 

[Megahertz07]

Did you remove the CPU or only the heat sink?
Take out the PSU and the battery and check your memory. Clean the contacts with a contact cleaner. Be sure to place it well into the slot.

 

[ICIT2LOL]

The optical drive is an easy fix and they are cheap enough.
Now are you sure you engaged all those ribbon cables properly because as you know they do have lock in tabs on them. Also did you make sure the CPU was not overly secured down?

Also did you clean the "rad" out while you were cleaning the machine - to check shine a very bright into the fan aperture and look through the air outlet if you cannot see any light then you need to clean that rad.

This is how I do it
CLEANING A LAPTOP FAN & COOLER RAD
The thing you do is to turn over the laptop and shine a very bright light into the air intake aperture (you will see the fan there) and then while doing that look at the outlet vent on the end of the laptop you should see the light quite clearly shining through the cooling " radiator" if not - it is clogged and will need cleaning as will probably the fan opening.
You can do this by blowing it out using a compressed air can in short bursts.
BUT ONE WORD OF WARNING DO NOT blow the air into the fan opening without inserting say a plastic rod or large cable tie to stop the fan from spinning as the air blast will spin the fan at a very high speed that it is not designed to take and may wreck the bearing!!
To clean the slots in the radiator use a pipe cleaner or one of those craft covered wire sticks - they are referred to as chenille sticks - see pic. But do be very careful not to be overly heavy handed you will find it might take a second or two or a few minutes to clear the heavier build ups.

 

[Digerati]

and finally applied new thermal paste

Why? Note that TIM (thermal interface material) will easily last 10, 15 years or even longer AS LONG AS the cured bond between the mating surfaces is NEVER broken.

You NEVER need to replace TIM just because it is X number of years old. Remember, the purpose of TIM is to ONLY fill the microscopic pits and valleys in the CPU and heatsink mating surfaces to push out any trapped insulating air. Even if the TIM has dried out, it does not need to be replaced because the solids that remain are still occupying that space preventing any insulating air from getting in.

It is the solids in the TIM that do the work. The ONLY reason TIM has any liquid component to it is so it can be squeezed out of the tube and spread across the device easily, evenly, and smoothly.

If anyone says TIM needs to be replaced just because some arbitrary amount of time has passed, demand they provide a link to any CPU or GPU maker, motherboard maker, PC or notebook maker, graphics card maker, TIM maker, white paper or technical study that says TIM needs to be regularly replaced.

There are two main problems with replacing the TIM. (1) Too often the CPU or socket is damaged due to mishandling - typically due to ESD or rough handling. Did you take the essential ESD control procedures? Note a static discharge (spark or electrical "arc") from your finger tips can torch a Grand Canyon sized trench (microscopically speaking) through 1000s of transistor gates on a CPU - yet the ESD can be so tiny, you (we as humans) are incapable of feeling, seeing, or hearing that discharge.

(2) Properly cleaning the mating surfaces is also essential. You never - as in NEVER EVER - just add more TIM. You MUST always thoroughly clean the two mating surfaces before applying a new layer of TIM. And then the new layer of TIM MUST be properly applied. It must be a thin a layer as possible while still providing complete coverage across the CPU die. The most effective transfer of heat occurs with direct metal-to-metal contacts of the mating surfaces. So any excess TIM is actually in the way and counterproductive to the most efficient transfer of heat.

Cleaning the interior of our computers of heat trapping dust is essential (and unfortunately, a real challenge with notebooks). But replacing the TIM just because it has not been done before or in awhile is not.

You say you were grounded the whole time - grounded to what? You don't need to be grounded to "Earth ground" but you do need to be grounded to the computer - that is, you and the computer must be at a "common ground". This ensures there is no "difference of potential" between you, thus preventing any "arc".

Then you said there is a chance static hit the CPU. That is my fear too.

 

[OverEight]

Okay, I've managed to get it working again (onto the login screen) with only minimal physical damage in the form of a busted touchpad, although it doesn't really matter given that I only use the mouse anyway. Right now I'm trying to get the keyboard back on, which is providing to be really irritating and fiddly. Once I've done that I should be able to log on and check the temperature, and all of this should hopefully be worthwhile. And don't worry I made sure to clean off the old, residual paste before applying new paste.

 

[Megahertz07]

If the touchpad and / or the keyboard isn't working is because the flat cable wasn't fit correctly into the slot. That's why I don't like laptops.
Just to know, what was the problem?

 

[OverEight]

https://i.imgur.com/vlFfCZ5.jpg

Okay all is good now. It took forever, but I've managed to reassemble it successfully, and now the temperature has decreased. Under high-load it used to overheat, but now it maxes out at 75c.

It was all worth it in the end. Thanks for the help.

 

[Megahertz07]

Great!!! Congratulations.

Please mark this treat as solved.

 

[ICIT2LOL]

Good stuff and if you ever have to do stuff to the machine again see this site Disassemble, repair, upgrade Toshiba laptop yourself.

just pick out your model and do read the newbie tips it gives good advice on those ribbon cable connections

As Itaegrid pointed out re the TIM personally I do any compound replacing with these products - not all will agree but there never has been agreement on this forum about what one should use but I have used many and these are the ones I always come back to
Arctic Silver Incorporated - ArctiClean & Arctic Silver Incorporated - Arctic Silver 5

 

[Digerati]

but now it maxes out at 75c.

That's still too hot for me.

Depending on the TIM you used, it may come down a few degrees as it cures over the next couple days. But if doesn't you still have problems. Maybe your fan is not spinning properly. Or something is blocking properly air flow.

 

[Megahertz07]

If you compare a desktop heat sink with the one used on a laptop you understand why the temperatures on a a laptop are high.
All old laptops work with high temperatures.

 

[Digerati]

If you compare a desktop heat sink with the one used on a laptop you understand why the temperatures on a a laptop are high.

Of course notebooks run inherently warmer. But 75°C is still too warm.

And old has nothing to do with it. In fact newer laptops tend to be more heat sensitive simply because they are more powerful but at the same time, thinner. Notebook makers can pack in the power but not the cooling of a PC. But again, 75°C is still too warm. It should not hurt anything IF all the thermal protection features are working properly - but it means the system will throttle back in performance sooner and more frequently because of heat.

@ OverEight - when you say "high load", what is actually running and what is the CPU utilization at that time? What is the temp when idle?

 

[Megahertz07]

I've seen Core 2 duo laptops (Sony) where CPU were running at 85ºC and GPU (NVidia) above 95ºC.
Old CPUs like Core 2 duo were 45nm and new Skylake are 14nm thick. So for the same processing, the old generates a lot more energy waste (heat).
From Intel: (I5 6600)
Thermal Trip: The processor protects itself from catastrophic overheating by use of an internal thermal sensor. This sensor is set well above the normal operating temperature to ensure that there are no false trips. The processor will stop all execution when the junction temperature exceeds approximately 130 °C. This is signaled to the system by the THERMTRIP# pin.

Junction temperature it's a lot more hot than case temperature, but as you can see, 75ºC it's normal, specially in laptops.

 

[ICIT2LOL]

Well my two cents worth is that the CPU has a Tcase of 100C and taking into account as the OP has stated under full load (CPU being turboed) and not forgetting it also has to HD graphics onboard also being driven - 75C although I would prefer it to be closer to 55-60C - is not that unreasonable.
Plus we are talking laptop here and cooling is always a problem because of the confined space and minimal air venting to the internal casing.

I am just curious as to whether he did what I asked and looked for crud in the cooling "rad"

 

[Digerati]

I've seen Core 2 duo laptops (Sony) where CPU were running at 85ºC and GPU (NVidia) above 95ºC.
Old CPUs like Core 2 duo were 45nm and new Skylake are 14nm thick. So for the same processing, the old generates a lot more energy waste (heat).
From Intel: (I5 6600)
Thermal Trip: The processor protects itself from catastrophic overheating by use of an internal thermal sensor. This sensor is set well above the normal operating temperature to ensure that there are no false trips. The processor will stop all execution when the junction temperature exceeds approximately 130 °C. This is signaled to the system by the THERMTRIP# pin.

Junction temperature it's a lot more hot than case temperature, but as you can see, 75ºC it's normal, specially in laptops.

This is all a bunch of BS! Why are you referencing CPUs that don't apply here? That just obfuscates this issue. The OP has a Core i5-2450M. That is NOT a Core 2 Duo, nor is it an i5 6600. To pretend the characteristics of one CPU applies to all is just silly. Even the two you referenced are totally different and have no bearing in the OPs issue.

And BTW, I have an i5 6600 in this system. NO WAY can it tolerate 130°C.

75°C is still a "safe" level for the OP's processor, but no way is that "normal" - especially when we don't know yet what "high load" means in this case, or what the idle temps are.

 

[OverEight]

@ OverEight - when you say "high load", what is actually running and what is the CPU utilization at that time? What is the temp when idle?

High-load would be 80%+ CPU load.

Under slight/idle load, check the link I posted a link to Imgur on my previous post.

To be fair it wasn't even this cool when I first got it, so basically this is the best I can get it. You can't overcome bad laptop case design, and this laptop is exactly that.

 

[Digerati]

Okay, 52-53°C at idle is not bad, depending on your ambient (room) temps.

You can't overcome bad laptop case design, and this laptop is exactly that.

I don't think it fair to call it a bad laptop design. Heat issues are inherent in all laptops. I would call it bad or misleading marketing for the entire laptop industry. IMO, there is no such thing as a good "gaming laptop" or a "desktop replacement" laptop.

The problem is, users are demanding more power, but at the same time, they are also demanding thinner and lighter laptops as well. PC makers can pack the power of a PC into a tiny laptop case, but not the cooling. Consider even full PC cases are challenged to keep a gaming PC properly cooled and a PC case supports many large (wide and thick) fans through many square inches of vents.

FTR, I have a Toshiba i5 as well and it typically runs about 46 - 48° with normal use - normal being doing tasks like surfing the Internet, email, or submitting forum posts. It jumps to 65 - 68° when pushed. When it climbs higher, I know it is time to clean out the dust and/or put it on a cooler pad.

You did not state the model number of your Toshiba so we don't know the size. Mine has a 16.5 inch monitor so fortunately it supports a pretty wide fan. Though again, because laptops are thin, that fan is not very thick so it cannot grab lots of air while spinning. If I am going to task it for long periods of time, I use my laptop cooling pad - which I recommend you check out. Make sure you get one that has an external power source so it does not put even greater demand on the notebook it is trying to cool.