HP EliteDesk 705 G4 Small Form Factor PC

[Rick3000]

The computer was working fine, but I wanted to change some BIOS settings and unselect PCIE 16 to see if the computer recognized the onboard graphics cards just for testing. It doesn't boot anymore. Three long and three short graphics cards were not detected. I tried the Onboard and the PCIE16 R7 430, but they were still the same. I reset CMOS, no luck. Unable to get into BIOS, beeps come first and make the computer unusable. The CMOS button was pressed several times following manual instructions, disconnecting the power supply. I also removed the battery, but it is still not getting into BIOS or Windows. It beeps three longs and three shorts. Is there any other way to reset it to the default and boot it into CMOS? Help is appreciated.

[BeemerBiker]

There is something wrong if the beep codes are sounding off like that.

You have done everything correct to try to recovery.

Possibly the internal graphics is defective.  What caused you to try to force the video to the internal graphics?

Was there a video problem to start with?

I did something very similar on my Z400. I set both of the PCIe x16 to "compute only" which basically disabled the video and the system no long booted.  I had to put a riser card in the x1 socket and plug my Nvidia graphics card into the riser.

When you disabled PCIE16 you disabled the x16 slot but possibly the x1 slot will still work.  That was what saved me.

I think this is your motherboard

look at the x1 socket and see if it has an open back.

The above image shows the socket is NOT open backed.

If the back is not open then you need a riser

I do not know if it will work but you can try a riser such as this

https://www.amazon.com/Flexible-PCI-Express-Riser-Cable/dp/B00KZIAE1C

put your video card into in and see if you can power up and get into the BIOS.

Make sure you do not put it in backwards or offset by mistake or both the video card and the motherboard may be ruined.

goes like shown here.  Make sure both sets of pins are fully in the socket and unplug power before inserting.

good luck!