Device switches on and off in three-second intervals, preventing it from posting or booting into BIOS.
Device switches on and off in three-second intervals, preventing it from posting or booting into BIOS.
Hey there, newbie here! Just started posting and I’m stuck. My PC built in 2013 suddenly flips on and off every three seconds. I can’t get it to start up or enter BIOS. Also, the LEDs on my motherboard—MBIOS and BBIOS—keep switching back and forth. When I power it up, the BBIOS LED lights up for a second, then turns off and switches to MBIOS, which immediately shuts down and restarts after three seconds, but now MBIOS stays on and flashes off right away. If I leave it on, it keeps cycling between these two LEDs.
I’ve tried everything step by step: changed RAM, removed GPU (including PSU cables and the slot), pulled out all peripherals and HDDs (disconnected SATA and power), even took off the battery for a minute and used a screwdriver to reset CMOS. Nothing worked. Now I’m left with a 4+4 pin CPU and a 24-pin one—still nothing.
I’m really hoping someone can help me figure this out. My goal is to give this machine to my younger brother so he can play games while I build a new one. His laptop is in shambles, just held together with duct tape. My specs are pretty standard: i5-4690K @ 4.6GHz (overclocked for years), Gigabyte Z97X-UD5H, MSI gaming R9 290X, and a bunch of RAM and storage. All these details have stayed the same for over five years.
Any advice would be super appreciated. Thanks a ton!
It might be a minor issue where the device contacts the case. Remove all components from the case and save them to a phonebook. Attempt to restart the system. If it functions correctly, a short could be present. If not, the board or CPU is likely faulty (probably the board).
Sorry that didn't work. It seems the motherboard or the CPU is the issue. I'd install a very inexpensive CPU, the cheapest one it supports, and test again. If it still fails, the problem is likely with the board itself. If it powers up, then the CPU is the culprit.
I identified the problem but none of the solutions seem effective—it's actually the motherboard, especially the BIOS ICs. I've tested shorting them, yet the main BIOS IC doesn't appear to make contact. For details: the forum thread on Overclockers and another guide on forcing BIOS backups.
BIOS issues are frustrating, but there’s still a chance to recover. The MOBO appears to be gone, though an alternative BIOS might exist. Your motherboards feature a dual BIOS switch—use it to boot from the secondary BIOS if needed. After disconnecting the board, set the switch to the secondary position and the system should start up again. I captured a photo for reference. You can attempt to repair the corrupted BIOS and re-flash it. Resetting the settings again might help, especially after removing the silver battery for a day, which seems effective in my experience.
Hey there, Seagate. Glad you got it! I checked and tried what you mentioned—switching off dual BIOS mode and using BBIOS. The boot loop stopped, but nothing appears on the screen. The board stays on power, yet the RAM LEDs stay off, and the Debug display isn’t showing any codes. I set up with just the CPU and one RAM stick, and the output comes from my CPU’s Intel HD graphics via both DVI and HDMI ports.