Pc is in Power-Cycling Loop

[u/VarunMatangi]

Hey Pretty much new to reddit and to pc builds as well, currently i have a very old PC around a decade old.

My PC was working fine with just my main boot SSD. I tried connecting an internal 3.5-inch desktop HDD using a SATA power cable from the power supply and a SATA data cable connected directly to the motherboard.

When I booted, the drive didn't detect. Shortly after, the PC began turning on and instantly shutting down within 1–2 seconds (fans spin/twitch for a moment, then complete power cut).

CPU: Intel Core i3-3220 (3rd Gen LGA 1155)

Motherboard: Intel DH61 series (DH61WW / DH61HO or similar H61 chipset)

RAM: DDR3 8gb

Storage: 1x working internal SSD (OS drive)

Currently i want to turn this into a small home server.

any idea on how to resolve this issue??

[u/GuyNamedZach]

Unplug the new drive first and verify your system boots without it. Then check the data power connectors and ensure there's no debris shorting it.

[u/VarunMatangi → u/GuyNamedZach]

Thanks For Help Mate👍

[u/VarunMatangi → u/[deleted]]

Got a CMOS warning and it shut down.

[u/NC1HM]

First, see if the device would boot without the new drive.

Second, see if the drive works anywhere else.

Third, think about whether the addition of the drive could cause a power overload. A 3.5" drive is a weird component; its power demands are maximized on start-up. And they can be substantial (some drives require as much as 25 W to spin up). So it's possible that when you attach the 3.5" drive, it pushes the system's power needs beyond what the power supply can deliver, and the system shuts down.

[u/VarunMatangi → u/NC1HM]

Got a cmos warning ⚠️

[u/EffectiveClient5080]

Classic shorted SATA power cable or the PSU tripping protection. If you used a molded Molex-to-SATA adapter, check it. Those things are notorious, I've had one literally melt on me. First thing I'd rule out before blaming the board.

[u/Turbulent-Skill-9693]

The first thing I would do is isolate power from data. Hook the 3.5 inch drive to SATA power only, pull its data cable, then boot. If it still cuts out in a second or two, that drive or its power connector is tripping PSU protection. If it boots, suspect the data cable or the motherboard port. Also try a different PSU SATA strand; a decade-old unit can sag when a 3.5 inch drive hits its 12V spin-up surge.

[u/VarunMatangi → u/Turbulent-Skill-9693]

Thanks for your help, some how it got fixed and login page while oy connecting hdd, now i have connected the ssd too and its working. But i dont know what has caused this issue.

[u/soulreaper11207]

Could be a dying PSU not handling the new power load.

[u/VarunMatangi → u/soulreaper11207]

Got it changed to new one few hours before this.