Question PC boots only after several tries

[Ediolot]

Hello ! I would like to ask if someone has any insight to offer for my issue.

My desktop PC takes several tries to boot. Currently, my boot process is the following:

1. Push the start button on the case
2. PC starts (fans and lights)
3. PC reaches the BIOS screen but is stuck there (function keys do nothing)
4. Push the start button to shut down
5. Turn off the switch on the power supply and push the start button several times afterwards to make sure there is no power
6. Shortcut the reset pins on the motherboard for the BIOS
7. Turn back on the switch on the power supply
8. Push the start button
9. PC starts (fans and lights but no BIOS, screen is black all the time)
10. PC shut downs by itself
11. PC starts by itself
12. PC reaches the BIOS screen (function keys do nothing)
13. PC shut downs by itself
14. PC starts by itself
15. PC reaches the BIOS screen (not sure if keys do work here, I think they do)
16. Windows starts

The process in video is here (starting from step 8) https://drive.google.com/file/d/1VOySFkSv5GdQ5mDcAlVIj8CqHtKLpcrP/view?usp=sharing (no sound)

My specs:

• Windows 11
• CPU: Intel Core i7-9700K 3.6Ghz (~2 years old)
• RAM: 2x 16GB Kingston HyperX Predator DDR4 2666 PC4-21300 (~2 years old)
• Motherboard: Gigabyte B365M-DS3H (~2 years old)
• SSD: Crucial P1 SSD 1TB 3D NAND NVMe PCIe M.2 (~2 years old)
• GPU: Nvidia RTX 2060 ASUS (~4 years old maybe)
• Hard Drive: Western Digital WD10EZEX (probably more than 6 years old)
• PSU: ATX-850-80-4 850W Power Green (probably more than 6 years old)
• (Also, an external USB-3 hard drive)

Some things I have tried:

• Running memory tests on the RAM with an image on an USB stick (I dont remember this one that much, it was long ago, but there were no errors)
• I recall configuring the RAM speed / frequency or some other similar options in the BIOS according to some posts, nothing worked and I reverted everything back to the original configuration
• Running tests on the SSD and the Hard Drive, everything is okay
• Swapping RAM sticks between different slots
• Some months ago I tried starting with or without the GPU connected, no difference
• I recently tried running with a different PSU I had around, this one was however 550W only. The PC starts (lights and fans) but no BIOS screen and shut downs again, this process is repeated infinitely it seems (see video here: https://drive.google.com/file/d/1VRZx1lN_PSR9oxwwC0UsIEtTzWMU3nhK/view?usp=sharing, no sound)

Some problems I have had before with the same PC:

• Two months ago, everything worked perfectly fine
• Around the first half of the year, sometimes, the PC took several times to boot but I had never had the problem of being stuck in the BIOS and needing to reset it with the pins on the motherboard
• In the past year 2021, I remember having some issues with my system not detecting any Windows installation. I tried disconnecting and connecting back again the SSD when this happened and it worked. I also remember having one or two blue screens related to the SSD or the watchdog maybe (I think)

My current plan is to swap the PSU with a newer one, then try replacing the motherboard, but I'm not sure what to do next. Any advice is welcome, thanks !

 

[Lutfij]

Welcome to the forums, newcomer!

PSU: ATX-850-80-4 850W Power Green (probably more than 6 years old)
Got a link to that PSU?

recently tried running with a different PSU I had around, this one was however 550W only
A link/make /model to this unit and it's age will also help us two fold.

 

[geofelt]

I think the motherboard bios is searching for a setup that works.
Usually, this is for a ram setting .

One possibility is that the cr2032 battery has failed and will no longer hold bios setting changes over a full unplugged power off.

Your motherboard has integrated graphics. Do some testing without the discrete gpu.

I suspect that you have a psu issue.

 

[Ediolot]

Got a link to that PSU?

Since it's an old one, I dont really have a link but I can share the specs on the label (850W):

While these are the specs of the even older one I had around (550W, maybe 12 years or more):

One possibility is that the cr2032 battery has failed and will no longer hold bios setting changes over a full unplugged power off.

I already tried measuring the voltage of the previous battery and it was okay. I did swap it for a new battery anyway just in case but the problem is still there

Your motherboard has integrated graphics. Do some testing without the discrete gpu.

I have tested this before but I tried again anyways. The problem persist in all these cases:

• No GPU (RTX 2060)
• No GPU & No HDD
• No GPU & No HDD & Nothing else connected but an HDMI

I also did test my current Power Green PSU (850W) measuring the voltages with a tester without any meaningful conclusion.

• Measuring +12V: https://drive.google.com/file/d/1Vbt_A7FUacOv0EICl5hXxr2BE1MJZFX3/view?usp=sharing
  • 12V on first boot, decreases a little and then drops to 0. Same thing on the second boot. And it holds on the third boot where Windows start (I turn it off at the end)
• Measuring +5V: https://drive.google.com/file/d/1VmpLsX4hvbWhMSP8vQsRQ-YHBzoPAbzq/view?usp=sharing
  • Same thing
• Measuring +12V on the really old PSU just for reference: https://drive.google.com/file/d/1WBTtDYbOeBQ9XVcP_M2L2Kk3ZX7qGlc1/view?usp=sharing
  • It's high (12V) but periodically drops
• Also tried measuring the PSU pins PS_ON and PWR_OK but since I dont have an oscilloscope at hand the measurement might not be very useful
  • PS_ON https://drive.google.com/file/d/1W77HRK7NPVNUBLKL0qnAuuVGkCuAGgay/view?usp=sharing
    • Around 3.9V when the PC is off. Jumps to around 100mV when PC is on. Goes back once to 3.9V in each boot attempt
  • PWR_OK https://drive.google.com/file/d/1VzNrdr1GmZ526d642x7eBa1BWpqqZaly/view?usp=sharing
    • By default at 0V, jumps to 5V when PC is on. Goes back to 0V once in each boot attempt

In case it was some boot order problem I also checked the boot order and everything seems okay:

• Boot option Priorities
  • Boot Option #1 -> Windows Boot Manager (CT1000P1SSD8)
• Fast Boot -> Disabled