Repairs - ASUS TUF FC705G fan replacement

Notes about the replacement of both fans (CPU/GPU) to an Game computer ASUS TUF FX705G.

The PC is a game laptop and fans are really a necessity to dissipate the heat generated by the CPU and the embedded GPU.
When they fails (not if, when) the system become quite unusable, noisy and incredibly hot even on the keyboard.

Problem description

The PC in this description has overheating problems, very likely due to too much dust in the fans (they are making too much noise as well) and the heatsink ducts.

The overheating lately become so bad to don't be able to touch the keyboard after a while the PC was running.

Critical things to expect

After reviewing documentation for the operation, there are few things to pay attention to : 

• Around the laptop border there are places with there is a "conductive foam" insulation.
  If for any reason a piece of metal touch the foam and the mobo, is possible to create a short circuit somewhere on the mobo
  It means that during the opening or closing operations of the back plate is important to DON'T use metallic tools to poke inside and pay very close attention
• First thing to do after removing the back cover is to detach the battery and discharge the circuit turning on the PC! 
• To remove the fans might be necessary to lift partially the mobo, paying attention to don't damage anything.
  
• In theory should NOT be necessary to remove the heatsink (the fans are installed in the heatsink) but if it is necessary, then will be necessary to :
• remove the heatsink paste from both heatsink and components
• clean up with alcohol both heatsink and components
• re-paste the components before to reattach the heatsink

Shopping list

OK, for this operation is necessary to have :

• paper towels to protect the area and to be used to clean
• alcohol 90% 
• screwdriver with different bits, mainly a Philips bite will be necessary
• plastic tools to pry open the back, the ones used to work on phones are perfect
• small pliers
• container to put screws and other small parts if necessary
• just in case, a thermal paste in case to re-paste the heatsink if removed
• two new fans

Doing it 

First of all I prepared few sheets of shop towels to protect the laptop on a table, then started to remove the screws at the bottom.

It is important to note that there are 3 different size (in length) of these screws.
So when is time to reassembly pay attention to what screw goes in a hole :) 

Since I already opened that specific laptop time ago to clean it up (just remove the dust without disassemble it or change parts) it was relatively clean, of course the fans were a totally different matter.
The original fans (one for the CPU and one for the GPU) were quite dirty and very probably damaged, aka they were generating quite a noise without providing enough flow to really cool down the poor machine.

The computer just opened

In the picture above, taken after removing the back, is possible to note that the battery (of course) is still connected to the motherboard and there is not much dust visible ... visible is the key word here.

Anyway, the FIRST thing to do is to disconnect the battery !
No need to remove it, but be sure to disconnect it !   
Not doing so there is a quite high risk to create a short circuit when removing the fans and fry the mobo.
For safety, until the battery is connected, USE ONLY PLASTIC TOOLS !!   
This limit the possibility to create short circuits.

CPU Fan

At this point I started to remove first the fan on the right (CPU fan).
There are two screws and one cable (other than the fan one) need to be disconnected.  Be careful doing so, the connection is made on a flexible PCB so is quite delicate.

Then disconnect the fan (remember how is connected or better, do a picture so you can see how to reassemble the new one.

CPU Fan connections and placement

Now, after removing the two screws (caution, they have different length) and disconnecting the cables, in order to remove the fan there are two choices :

• disconnect the heat sink from the mother board
• lift GENTLY the motherboard enough to slide out the fan

The first solution would be OK if there was not the need to re-paste the area !
SO I opted for the second one and it worked great.  
Just be VERY VERY gently and don't lift too much, with the risk to crack the mother board.

The fan has a kind of "hook" that  helps to keep the fan in the right position.

After removing the fan be sure to remove dust, cleaning the ducts with a vacuum cleaner and then using a paper towel with some alcohol, remove all the grime and dust from the fan area.

CPU Fan area after fan removal

To reinsert the new one just do the same, lift gently the mother board enough to slide in the new fan, position it, screw it to the mother board and then reconnect all the cables.

GPU fan

This one is more tricky.

There are 3 screws (this time all the same length) and there is the need to detach only the fan connection, however mechanically is like a puzzle.

GPU Fan and connections

Without removing the heatsink you need to find a combination of moves that allow to remove the the fan lifting the mobo and and the same time, tilting the fan in order to slide one of the screwed supports below the heatsink !

In a way would be much easier to remove the heatsink but with some patient (the importance to play tetris :) ) I was able finally to slide it out without touching critical parts of the mother board.

As the other one, I vacuumed and cleaned up thoroughly the area and then replaced the fan.

GPU fan area after removal

Again, is very very tricky and you'll need lot of patience.
Very very important to avoid to touch components on the mother board when reinserting the fan since one "leg" has to go below the heatsink in the front area and another one goes below the heatsink in the back area.

 

Adding 1Tbyte HD

The first picture shows an area where there is a HD bay empty.
Having around a 3.5 1 TB HD I just added it.

Unscrew the HD support, screw in it the HD (needs to be mounted upside down, i.e. the bottom of the HD visible. 

I did pre-format the HD in NTSC before to install it and it was seen by the OS immediately when the system restarted.

Resources

• Amazon - decent pair fans (expensive/slow/with warranty) 
• Amazon - base (cheap/fast/no warranty)
• Amazon - base (very cheap/fast/no warranty)
• iFixIt - FX705G fan replacement