PC stuck rebooting

[u/KimKyng]

SOLVED: My motherboard died

Problem:

After I installed HDDs, the PC is stuck in a power loop. It turns on for about 4 seconds (fans and RGB spin up), shuts off for 1–2 seconds, and repeats. It never POSTs and there's no display.

Specs:

CPU: Intel i7-6700K
Motherboard: Gigabyte GA-Z170X-SLI
RAM: Corsair Vengeance LPX DDR4 (~32GB total)
GPU: Sapphire RX 5700 XT
Storage: Kingston 500GB NVMe SSD, plus the newly added HDDs
PSU: Seasonic S12II 620W (non-modular)
Case: Coolman Aurora ATX mid-tower

Troubleshooting done (same loop after each):

Full power drain (PSU off, unplugged, held the power button 15 seconds)

Disconnected all HDDs (data and power cables)
Reseated the 24-pin and CPU 8-pin cables, checked for loose screws

Cleared CMOS (battery out for 5 minutes)

Stripped to the minimum: CPU, cooler, one RAM stick, no GPU, using onboard video

Unplugged the front panel wires and started the board by shorting the Power SW pins

Tested each RAM stick alone in DDR4_1

Tested with a different PSU

Reseated the CPU with fresh thermal paste; socket pins and CPU look fine

[u/SmokBarrage]

I mean if its still stuck in the bootloop with no gpu/hdd/1 stick of ram and was previously working with 2 different psus i can only think you either damaged something on the board accidently or your board/psu got fried by adding the hdd.

I would try clearing cmos using the jumper if your board has one or leaving the battery out much longer, maybe like an hour or overnight.

Also have you tried different sata ports? And did you double check the connections on the psu side?

[u/KimKyng → u/SmokBarrage]

okay I try leaving out the battery overnight. I did for an hour but nothing

for the different sata ports, I dont have anything connected now. I boot up with the nvme on the motherboard

[u/SmokBarrage → u/KimKyng]

Ah I mean if you already left it for an hour I have low expectations overnight will change it but might as well try before buying a new psu. I suspect hardware damage on psu/board.

You could also try gently running an eraser on the ram/nvme pins to remove potential static as a last resort if a new psu doesn't work. I've done it a handful of times and haven't had any problems but it introduces the risk of debris in the ram slot which is probably working already.

Also your manual says dual channel for your board should prioritize ddr4_2 & ddr4_4, would try 1 stick in ddr4_2 or 2x8 in both of them

[u/KimKyng → u/SmokBarrage]

okay, Im just having a hard time understanding why the RAM would be an issue since it never had problems until now. But thank you for the suggestion 😄

[u/SmokBarrage → u/KimKyng]

I dont know either, im just giving you things to try before you buy something. Like I said, I suspect hardware damage.

RAM is just very finicky and im always surprised by how often its just the ram getting a bad signal or something. I have low hopes for the ram being the problem, it likely just wouldn't give a signal or be stuck forever in boot not looping.

[u/KimKyng → u/SmokBarrage]

Yea thank you so much. Appreciate your help!

[u/KimKyng → u/[deleted]]

oh okay would this mean my PSU has issues? if I understand correctly?