PC fails to boot 4 times, then Windows runs perfectly fine

HToDodongo

Prominent
May 6, 2017
2
0
510
Hi, i've recently upgraded my graphics card and the power supply,
After that weird things happend.

When i boot up the PC, it beeps and shows me the normal booting screen with the keys for entering the BIOS and so on.
That screen stays for about 30 seconds, after that it beeps again, then stays for another 30s and beep. again.. and so on.
After the 4th beep Windows boots like nothings happend, and it works perfectly fine.

So i thought, maybe look at the boot order, but i can't access the BIOS anymore.
In the first 3 "beeps" the keys are doing nothing, (although i can hear a tiny beep everytime i press a key on the keyboard, so thats not the problem).
After the 4th beep, if i hit delete, it just brings me to a black screen (tried on different monitors).
If i hit F8 instead the windows recovery pops up with in that case useless options.

I've also tried disconnecting all USB devices + the HDD and CD-Drive, removing the Mainboard Battery for a while, using different outputs on the graphic card (HDMI, DVI, on monitor and TV)... nothing worked.

Can anybody help me?

My specs:
- Windows 7 Home Premium
- Intel I5 2320 @ 3 GHz
- Mainboard MEDION MS-7728
- 2x4 GB DDR3 RAM
- Gigabyte Geforce GTX 960 (2GB)
- 120 GB Samsung SSD (for Windows only)
- 1 TB HDD
- PSU: be quiet Pure Power 10 (500W)
 

HToDodongo

Prominent
May 6, 2017
2
0
510


It doesn't beep 4 times in a row, it's the normal startup beep, but 4 times repeated with ~30sec between them.
Like it's stuck in a loop, and don't accepting any input, until the 4th one
I've already googled for the codes, but there is none that waits 30 seconds.
Also everything else on the PC works fine once Windows is finally started.
 

Pedro_Casc

Commendable
Oct 15, 2016
5
0
1,520


Oh, I get it. I don't know what it is. You will have to wait to see if anyone has the answer.