When I press the power button, the fans start spinning, but there is no image on the monitor and the keyboard's Num Lock light stays off. I already cleaned and reseated the RAM, cleaned the RAM slot and processor, and replaced the CMOS battery. My motherboard has no diagnostic lights or error-code display. What should I check next to find the faulty component?
1 Answer
The system probably isn’t completing POST, so the spinning fans only confirm that the power supply is providing some power. Try starting with the minimum hardware: disconnect all drives, USB devices, and extra PCIe cards, then reseat the motherboard power connectors, CPU power connector, RAM, and graphics card. Test one RAM stick at a time in the recommended slot, and make sure the monitor cable is connected to the correct video output. If the processor has integrated graphics, remove the dedicated graphics card and test from the motherboard video port. Also check whether the board speaker can produce beep codes. If there is still no keyboard power or display, the likely causes are the power supply, motherboard, CPU, or RAM.
There are no diagnostic lights on the board, and the keyboard Num Lock light remains off as soon as the system starts. I’ll test it with only the essential components connected and check the power and video connections again.