I see the motherboard and gpus are dusty. I tried to use the home vacuum cleaner but did not work. Any suggestion on kind of vacuum cleaner to be used?
Buy some compressed air cans, shut down your rig, take out the GPUs, dust off the GPUs with compressed air, dust off the other components (MOBO, PSU, CPU cooler).
When taking apart GPU PCB from the cooler be sure to reapply thermal paste later/reseat thermal pads. Same goes for taking off the CPU cooler - reapply thermal paste later.