I can hear the fan RPM increasing, and maybe a couple of ticking sounds as the speed increases. Could be some debris in the fan or fan housing, or something simple like a paper tag on a wiring harness close by the accelerating airflow. Some level of disassembly will be required to find out what it is. I would not recommend application of vacuum cleaners or canned air without a proper inspection. Never spin up one of these pancake fans in this manner, as an overspin condition could occur leading to bearing damage and then it would be really noisy. If you have the MyASUS app loaded, you can run a System Diagnosis routine that includes bringing the cooling system fans up to speed. Proceeding to an inspection is something you should do only if you are comfortable with the disassembly and troubleshooting. You probably won't be able to see much from the inspection panel on the underside of the laptop. Typically, you can only see the hard drive(s) and RAM memory card slots. Further disassembly will require removal of this inspection panel first. I usually take a blank piece of typing paper (from my printer) and lay out a model of the laptop underside where I can place each screw I remove to insure they all go back where they came from. Screw lengths will usually vary, and you wouldn't want to put a longer screw in a shorter mount point. Popping off the bottom cover panel should be done carefully, using a proper tool called a spudger that won't damage the joints between the cover and laptop case proper. With the bottom panel removed, locate the blower housings for the CPU and GPU and note where they vent. If you have some canned air (for dislodging and cleaning dust) first take a small screwdriver and place it carefully into the air intake circular slot and lock the fan blades from rotating. Then take your canned air and apply a reverse flow into the external vent slot slowly moving across the whole opening. Be prepared for dislodged dust and hopefully whatever might be making that noise to exit the circular fan intake port. After this operation is completed to your satisfaction, you might want to look around the rest of the motherboard for dust and debris, which can be removed with the canned air, a vacuum cleaner, or what I use is a small paint brush. Reassembly is the reverse of the disassembly procedure. Hope this helps.
N71JQ-A1, G752VM-RB71, GX703HR-XB96
