Question No OS found / Cant get into bios

[Thebiz]

Hey folks!

Having a problem with this pc I built for a friend about a year ago. Not quite sure what they did to cause this problem but I can't figure it out.
This pops up when you turn the computer on . "An operating system wasn't found. Try disconnecting any drives that don't contain an operating system."
There seems to be no way to get into the bios as well.

Specs: Mobo Asus ex-b250 , Cpu Intel i5-7600, Psu Corsair Cx-M series Cx550, Ram Corsair Vengeance 16gb (2x8gb), Ssd Adata Su800 128gb, Hdd Seagate BarraCuda St2000dm006 2tb, OS Windows 10

Things I've tried:

1. Hitting F2 or Delete Key on start up
2. Disconnected all sata cables
3. Took CMOS battery out for over a hour
4. Put in flash drive with bootable Windows 10

Any help would mean a lot thanks .

 

[Ralston18]

Number 2: "Disconnected all sata cables." You did leave the boot (C drive) connected - correct?

Try a new CMOS battery.

 

[popatim]

It's the Del key for the board.
With the system unplugged from the wall & Drives disconnected, short the CLEAR RTC pins for a minute and then start it back up and hold the Del key down.
See if that works. to get into the bios.

 

[Thebiz]

Number 2: "Disconnected all sata cables." You did leave the boot (C drive) connected - correct?

Try a new CMOS battery.

I tried with them all disconnected and then just with the is drive connected.

 

[Thebiz]

So I swapped the battery for a new one and held down the del key and it came on. It did the Asus splash screen and went into windows. I turned it off to try it again and it won't work now.

 

[Thebiz]

It's the Del key for the board.
With the system unplugged from the wall & Drives disconnected, short the CLEAR RTC pins for a minute and then start it back up and hold the Del key down.
See if that works. to get into the bios.

I tried to short the CLEAR RTC pins not 100% sure it didn't anything or I did it right. Back at square one .

 

[Ralston18]

Try the preceeding suggestions.

Then, if no success or intermittent success, power down, unplug, and open the case.

Doublecheck that all cable connections, jumpers, cards, RAM, etc. are all fully and firmly in place.

Intermittent operation is often the result of something coming loose.

Over time due to heat related expansion and contraction system components slowly creep loose.

And connectivity is lost. Does not take much to cause some failure.

 

[jsmithepa]

After getting into BIOS and done the necessary configuration, if any, NOTE whether it has detected your SSD/HD (it should). Then do me a huge favor and hit F10 to save the settings and boot.

 

[Thebiz]

Try the preceeding suggestions.

Then, if no success or intermittent success, power down, unplug, and open the case.

Doublecheck that all cable connections, jumpers, cards, RAM, etc. are all fully and firmly in place.

Intermittent operation is often the result of something coming loose.

Over time due to heat related expansion and contraction system components slowly creep loose.

And connectivity is lost. Does not take much to cause some failure.

Just triple check all the connections even used new cables no luck .

 

[Ralston18]

Did you try @jsmithepa's suggestion to configure the BIOS and save the configuration (F10) after installing the new CMOS battery and completing the connection checks?

Starting to think that the PSU could be faulty....

Was it new when installed? Did your friend do a lot of gaming on the pc?

 

[Thebiz]

Did you try @jsmithepa's suggestion to configure the BIOS and save the configuration (F10) after installing the new CMOS battery and completing the connection checks?

Starting to think that the PSU could be faulty....

Was it new when installed? Did your friend do a lot of gaming on the pc?

I can no longer see the Bios im back to my main problem. After I swapped the cmos battery it booted straight to windows and was working fine. I turned it off to try to go to the bios and it started the "An operating system wasn't found. Try disconnecting any drives that don't contain an operating system." thing again. Everything was new when installed 1 year ago . No gaming on the pc it was just suppose to be a research pc .

 

[Ralston18]

No gaming - understood.

However the nature of the research could have been as equally demanding - no way for me to know in any case.

Do you have another known working PSU that could be installed?

 

[Thebiz]

No gaming - understood.

However the nature of the research could have been as equally demanding - no way for me to know in any case.

Do you have another known working PSU that could be installed?

Gonna have to get another one to try

 

[Thebiz]

Well I got a new psu and some new ram (just to see if that worked) and it had no change . Think it might just be a failed mobo?