# Disabled Secure Boot, flashed custom GPU bios, won't post



## paulr24 (Mar 24, 2007)

Hi all,

Here is my current situation:

Got a new HP desktop (Windows 10 Pro) with RX 580 GPU. Disabled Secure Boot in BIOS since I wanted to avoid potential issues from flashing custom GPU bios, then flashed the custom BIOS (nothing fancy, just modified some timings which worked for me in the past with another RX 580).
After rebooting it will not post and it gives 3 short beeps and 3 long beeps, which according to HP signifies that "the embedded controller has timed out waiting for BIOS to return from graphics initialization."
I tried pulling the GPU and plugging into integrated graphics via HDMI but got the same result. It could be that the integrated graphics are disabled (the ports were covered) but I can't seem to get into BIOS to check.
I tried swapping in a different GPU (not 100% it's working since I have no other PC to test with currently, but I have no reason to believe it's dead). Same result.
Tried removing and re-inserting the CMOS battery, then booted up with no GPU, then with RX 580, and then with other GPU. Same result each time.
Any suggestions as to what I should try next? I'm pretty stumped...


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## dmccoy (Oct 7, 2017)

Do you have a VGA cable that you can connect to monitor to at least get you in the bios to change to your video settings?


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## paulr24 (Mar 24, 2007)

dckeks said:


> Do you have a VGA cable that you can connect to monitor to at least get you in the bios to change to your video settings?


I do have a VGA cable but the integrated graphics only has HDMI ports and the GPU only has HDMI and DisplayPort.


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## dmccoy (Oct 7, 2017)

You should have a vga connector on your motherboard?


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## paulr24 (Mar 24, 2007)

dckeks said:


> You should have a vga connector on your motherboard?


Oh gotcha. I just checked and the motherboard doesn't appear to have a VGA connector unfortunately.


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## dmccoy (Oct 7, 2017)

Interesting, What is your make and model of motherboard or computer?


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## paulr24 (Mar 24, 2007)

dckeks said:


> Interesting, What is your make and model of motherboard or computer?


This is the one:
https://www.amazon.com/HP-Pavilion-...UTF8&qid=1516039904&sr=8-1&keywords=hp+rx+580

I can't seem to figure out the motherboard model. It says HP on it but I'm not seeing a model # (there is a serial # sticker but Googling what appears on that came up with nothing).


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## dmccoy (Oct 7, 2017)

Okay, I think this is yours and you are correct no VGA. When you connect to one of the HDMI ports and first turn on nothing shows at all on monitor?

Remove everything on the MB down to the very minimum and see if it will allow you to access the bios. Are you sure your cleared the cmos?

https://support.hp.com/us-en/document/c05634309


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## paulr24 (Mar 24, 2007)

dckeks said:


> Okay, I think this is yours and you are correct no VGA. When you connect to one of the HDMI ports and first turn on nothing shows at all on monitor?
> 
> Remove everything on the MB down to the very minimum and see if it will allow you to access the bios. Are you sure your cleared the cmos?
> 
> https://support.hp.com/us-en/document/c05634309


Yes, that's the motherboard! And yes, when I connect to one of the HDMI ports nothing shows on the monitor. I will try removing everything I can from the MB in a little bit, is there anything specifically that I should keep plugged in? And remove power from the optical drive, etc, as well?

As for the CMOS... I just realized that removing the battery alone isn't enough, my mistake! I just checked out the CMOS diagram on the MB doc you referred to. I unplugged power, set the CMOS jumper to clear, replugged power and booted up (same beeps), turned off, unplugged power, set CMOS jumper back to default, plugged power back in, booted up... still the same beep code.

FYI now I'm wondering if I may have mistakenly forgotten to enable legacy support in BIOS when I disabled Secure Boot, and if that could be causing this...


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## Lanctus (Jul 20, 2017)

When you log into BIOS and see the Boot options, under UEFI does it list Windows Boot Manager, or is there nothing there?


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## dmccoy (Oct 7, 2017)

He can’t get into bios I believe which is the main issue.


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## paulr24 (Mar 24, 2007)

dckeks said:


> He can't get into bios I believe which is the main issue.


Yep, exactly. As for what you said about removing everything from the MB down to the very minimum, what would you consider the minimum? HDD, fans, USB ports... anything else?


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## dmccoy (Oct 7, 2017)

Two approaches, either remove everything down to the cpu fan, one ram module and test and start adding after each test. 2. remove one item at a time and test after each


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## paulr24 (Mar 24, 2007)

I'm still troubleshooting with removing stuff from the MB and testing, no luck so far. One thing I wanted to mention is that after I press the power button the CPU fan is quite loud and seems to get louder and louder until I shut it off. I haven't let it stay on for more than a minute or so, trying not to burn out any components.


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## paulr24 (Mar 24, 2007)

Just to follow up, I tried removing components from the MB one by one but still have the same beep code. I found 2 other video cards and tried to see if I could get to post with either of them but got the same beep code there as well. I'm so confused, I would have thought that clearing the CMOS and using a different video card would get me past this issue when the only things that I did to this PC were flash the custom bios to the original GPU and disable Secure Boot... Could it be that the CMOS didn't clear somehow even though I tried both using the jumpers and removing the battery for 15 minutes?


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## dmccoy (Oct 7, 2017)

Do you get the same beep codes with the GPU removed?


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