I reset the PC and reinstalled Windows 11 on a 2 TB SSD after wiping both SSDs. Before reinstalling, I safely disconnected a separate HDD that contains important files. The computer worked normally after Windows, chipset, graphics, and Wi-Fi drivers were installed.
After shutting down and reconnecting the HDD, the PC briefly started and then completely powered off. Since then, it powers the fans and LEDs but usually does not reach the BIOS or produce video output. Testing the 600 W power supply with a voltmeter did not reveal an obvious problem.
The system has an i7-9700F, 16 GB of DDR4-3200 memory, an Omen motherboard, and either a GTX 1060 or GTX 1650 graphics card. With the graphics card removed, the system produced a beep pattern associated with a graphics problem. Swapping cards did not initially help. After resetting the CMOS and moving the RAM to another slot, the PC eventually displayed an image and booted normally. However, shutting down and reconnecting the HDD caused the same no-display condition to return.
What should I check next? Could reconnecting the HDD be exposing a power-delivery, SATA, short-circuit, RAM, or motherboard problem, and how can I safely test the components without risking the data on the HDD?
3 Answers
Start by disconnecting the HDD again and booting with only the Windows SSD connected. If the computer starts normally, inspect the HDD’s SATA power connector, SATA data cable, and the motherboard port. Try a different SATA data cable and a different motherboard SATA port, but do not repeatedly power the system on if the HDD makes unusual noises or causes an immediate shutdown. A faulty drive or shorted cable can trigger the power supply’s protection, although it is also possible that reconnecting the drive is only exposing an existing hardware problem.
A voltmeter test does not fully prove that a power supply is healthy. It can show correct idle voltages while the supply still fails under load or has a problem with a cable or connector. Reseat the 24-pin motherboard cable, CPU power cable, GPU power cable, RAM, and graphics card. Test with the minimum hardware: motherboard, CPU and cooler, one RAM stick, graphics card, and the Windows SSD. Leave the HDD, extra USB devices, and unnecessary drives disconnected.
The beep pattern is specific to the motherboard or system firmware, so check the exact Omen model’s service manual rather than relying on a general beep-code list. Clear the CMOS with the PC unplugged, then install one memory stick in the recommended slot and try each stick separately. Make sure the graphics card is fully seated and its auxiliary power connector is attached. Since the i7-9700F has no integrated graphics, the monitor must be connected to the graphics card, not the motherboard video ports.
Also avoid changing several parts at once. Get it to reliably reach the BIOS with the HDD disconnected, then reconnect one component at a time so you can identify exactly what causes the failure.
I used the same SATA port and cables as before, but I’ll try another port and cable with the HDD disconnected until the system is stable.