CPU Fan Failure?

I've been asked to work on Samsung R540 laptop with a faulty charger connection, but I can't find anything wrong with said connection. However, the unit powered down on me several times without warning, even though the battery still had plenty of power.

I noticed the area around the fan port was rather hot, so I installed Speed Fan to check the CPU temps (quad core), and they were going as high as 160° f ! After powering down the unit, I removed the back cover to check the fan ports, and they looked clean to me. I could have removed the fan itself, but that would have entailed removing the heat sinks, and I had no thermal paste on hand, so I left fan alone for the time being.

After reassembling the unit, I monitored CPU temps while installing Windows updates, and sure enough, the unit would shut as the processor heated up. Sitting the laptop on hard surface helped some, but not much. Ironically, you could hear the fan RPMs spinning up and down, but not enough to cool the CPU properly.

Does this sound like a fan issue, or something else? I sometimes wonder if the thermal paste has deteriorated and developed cracks. The laptop was sometimes used for gaming, and things can heat up quickly if the fan can't keep up. Does anyone know of software that can diagnose fan troubles? Speed Fan has not been any help in that regard.

 

Wouldn't hurt to clean the old thermal paste and redo it if there is even any thermal paste used on it. Don't think that everything now a days use thermal paste any more. Some use nothing.

 

As mentioned to you before, you really need to be using centigrade when reporting computer temps because that is how the entire industry does it - even here in America where Fahrenheit is typically used for everything else. 160°F doesn't tell me anything for a couple reasons. First, you didn't tell us what CPU it has and the R540 comes in several models, with different CPUs. This one, for example, has the i3 380M while this one has the 370M.

Assuming the i3 380M, as seen here, Intel (an American company like AMD) reports the maximum allowed Tjunction temp is 90°C or 105°C depending on the socket used. Note they are shown only in centigrade! So you need to tell Speedfan to report them in centigrade and use that from now on.

Note that 160°F = 71.1°C which is well within tolerances for that CPU. However there could be a threshold setting in the BIOS setup menu that is below 71°C.

And note there are other devices within a computer can are heat sensitive besides the CPU that affect computer stability. These include the chipset, RAM, drives, graphics, and more. So good air flow is necessary for more than just the CPU.

You might try blasting a desk fan down and across the notebook with all its covers off to see if that helps.

I am not aware of any processor that has a mounted heatsink that doesn't use TIM (thermal interface material). I would be interesting in see and reading about that, if you have a link, MrBill. Some extreme hobbyists use a "lapping" technique to use precision machine the mating surfaces to ensure the mating surfaces are perfectly flat and in those cases, TIM may not be needed - but that process definitely voids the warranty.

Note that TIM does not need to be replaced just because it is X number of years old. It can easily last 10, 15 years or longer. It will not deteriorate or go bad or need to be replaced as long as the cured bond is not broken. Even if it dries out, the solids that remain behind are still occupying the microscopic pits and valleys thus preventing any insulating air from getting in.

 

The full model number is: NP-R540-JA08US

Here is the processor info...

CPU Intel® Core™ i3-370M Processor , Intel® Core™ i3-370M Processor

Speed (GHz) 2.4GHz

CPU Cache 3MB​

I couldn't make up my mind about ordering a new fan, so I opted to remove the existing fan / heat sink assembly (which includes a flattened copper tube / pipe to distribute heat from the heat sink to the fan), and replace the old thermal paste.

After removing some tiny screws and a strip of black tape, I removed the fan itself, and it was then that I noticed a hidden layer of lint attached to the vent opening. It was a not a heavy layer, but it may have been enough to reduce the cooling efficiently of the fan. I cleaned the vent and fan with a toothbrush, cleaned the processor surface and heat sink assembly with alcohol and a coffee filter (had to scrap some of the old paste off with a plastic tool), and reapplied new paste.

So far, the laptop has not shut down on me even after removing and reinstalling some .net framework updates, but the processor temps are hovering between 50° and 60° Celsius at times. I think I'm going to return the unit to the owner, let them play with it, and see how it goes. I offered to refresh the operating system (Junk Ware Removal tool found some bad entries), but the owner declined.

 

It is important to remember that notebooks inherently run warmer than PCs. There is nothing wrong with 60°C.

Note too with some TIMs, they get a few degrees more efficient after they completely cure.