Question PC Shutdown randomly, temperature issue? Please help me

[DarberMax]

Hi, last month I've upgraded my GPU from a GTX 750ti to a Sapphire Radeon RX 580, during this month the PC started to shutdown randomly when I play games, no blue screen or other messages when i restart the PC, I only have to power off the PSU for 10 seconds and then power on the PC and everything returns to works fine.

No overclock and every driver is up to date (except the Realtek High Definition Audio Driver).
I admit that the cable management is not the best and there is a bit of dust inside the PC, but not so much to be significant.
I have 3 fans 120mm into the PC, two in the front and one in the back.

Is this a cooling/overheat issue? How can i resolve this?
Can it be a PSU related issue? Or can it be a Case (Airflow) issue?

And how can i have the temperature of every component an instant before the shutdown, there is any program that do this?

My components:

CPU: Ryzen 5 2600
GPU: Radeon RX 580
MoBo: Gigabyte B450M DS3H
RAM: HyperX Predator DDR4 (2 x 4GB)
PSU: iTek Rebel Series 700W 80Plus Bronze
Case: I dont remember the name but it's from iTek and is Full Tower

 

[Zephyl]

iTek Rebel Series? Doesn´t sound very reliable. This kind of thing usually is a result of the GPU not getting the power it needs, so either the cabling is loose or disconnected somewhere on the motherboard or GPU, or that generic PSU is causing issues.

 

[DarberMax]

Thank you for the reply, I will check the cables and try a different PSU, but I have another question: when I turn on the pc after one of those random shutdowns the GPU fans go to the maximum speed for about 5 secs, then they return to work in Smart Fans Mode, is this a normal?