Chosen Solution
My PS4’s fan spins rapidly after opening a game…and it shows “ps4 is too hot” but it isnt actually hot (as far as i know) and ive touched every sides of my ps4 and none of them are heating….other than the fan spins really fast
Usually it’s either bad mounting of the clamp (could be not screwed on tight and/or upside down) or no thermal paste / thermal paste wasn’t replaced after disassembling the PS4. Also need to ensure all thermal pads for the VRAM chips are present near the APU. Make sure to have thermal paste ready and clean up the PS4 up to the fan as this is strongly recommended: PlayStation 4 Fan Replacement