HP Compaq dc7800p Convertible Minitower PC - Just Spinning Fans

[Pankreas]

Greeting all. Apologies in advance if this has been answered somewhere or linked. 

I'm setting up a HP Compaq dc7800p Convertible Minitower PC with Linux OS, this is not the important part. I was checking out some of the GFX apps and realized that the Onboard VGA isn't going to make the cut. I had a spare Gigabyte GV-R725OC-2GI (rev. 2.0) card and installed it. This is where things gets interesting. 

As soon as I power on the workstation, the normal indicators are there for booting up, but then no display on either GFX card or onboard, no beep codes or led flashes just the system fans go into high speed and that's it. I suspected it might be the Power supply unit that is not strong enough, so I use a 500w one I had spare as well. Same thing is happening. 

reseating, power cycle reset, nothing has help thus far.

The workstation boots and functions as normal when I don't have the GFX card in.  I am pretty sure the card is functioning as it came out another workstation, but wasn't being used. I will double check this just to be sure. 

Is there something I might be missing?  like the workstation is using DDR-2 memory (currently 7GB) and the GFX card is DDR3. Bus Speeds? 

Any advice is appreciated.  Thank you Kindly  

[itsmyname]

@Pankreas --- this may be sacrilegious to an UBUNTU user, but Download Windows 10 (microsoft.com)

for free, and install it. During the install, click "I do not have a product key". The worst that can happen is that Windows will report "this copy of Windows 10 is not activated".  But, the big question is "does your video-card work when trying Windows 10" ?  Either it will, or it will not.  But, either way, you'll get some information about the compatibility, or lack thereof, between your motherboard and your video-card.

[Pankreas]

@itsmyname thank you. I'm not a hardcore ubuntu user, but want to get back into it. 

I do have another workstation with Win 10 on, and will confirm that the gfx card is indeed functional. Alternatively, I'll load win 10 on the HP Compaq workstation and see if there is any change. 

Note, I believe this is pre post, but I'll double check on that as well and check/feel for HDD activity. 

Thank you kindly. 

[Paul_Tikkanen]

Hi, @Pankreas 

I have a dc7800 CMT and what I believe the problem is that you are having is the R7-250 is too new a graphics card to run on such an old platform.

The R7-250 only requires a 250W power supply so lack of power isn't the issue.

The PC's 365W power supply is ample enough for many graphics cards.

The problem is that model card normally is used on newer desktop PC's with UEFI BIOS' and the dc7800's legacy BIOS is too old to support it.

I am running an AMD Radeon HD 6570 in my dc7800 CMT and it works with no problems at all.

You can probably pick up a used but tested and working HD 6570 on eBay for cheap.

If you are not running on BIOS v1.35, you may want to update the BIOS and see if that allows the R7-250 card to work by some outside chance.

Use the F10 BIOS flash method to update the BIOS. 

You don't need to be in any operating system to update the BIOS that way.

Let me know if you need instructions for doing that.

[Paul_Tikkanen]

Hi again, @Pankreas 

The reason your graphics card isn't working is not due to the UEFI BIOS thing.

I forgot that I had an AMD Radeon R7-450 graphics card in one of my HP 8200 Elite CMT's, so I removed it and installed it in my dc7800 CMT running on Windows 11 with BIOS version 1.35.

The card works great and W11 automatically installed the drivers for it.

So, my assumption is your PC is not running on BIOS v1.35, or for some unknown reason that specific brand/model card is not compatible.

The R7-450 is pretty much the same as the R7-250 except perhaps that mine has 4 GB of graphics memory.

[Pankreas]

Good day all. 

Firstly, thank you @Itsmyname and @Paul_Tikkanen for the quick and useful advice and replies. 

@Paul_Tikkanen you were right, my BIOS was not on V1.35, which I did update from V1.04.  The workstation is doing the same still currently as soon as I install the graphics card. 

I am yet to muster up the energy and dismantle my working pc and confirm the graphics card is 100% functional, and I will provide some further feedback. Just wanted to say thank you for the given advice and direction.  

[Paul_Tikkanen]

You're very welcome.

Sorry, that updating the BIOS to the latest version did not resolve the problem.

It must be the graphics card then, unless the PCIe x16 slot is no good.

[Pankreas]

Just a quick update. I am now suspecting the Graphics card to be at fault here. 

I did test the card in my other workstation, and no display on VGA or HDMI, there aren't fan spinning out of control or loudly, but there is no other activity either. 

I attempted to test that workstations graphics card in the HP compaq dc7800P, but I will have to take out the motherboard to be able to fit the card in as it has a secondary DVI port on an extended panel, the HP case layout and PCI slot placement isn't accommodating for a quick test. I should be able to get to it this weekend to test the slot, if that works it will confirm that the card is faulty, which I'll test on another system as well for good measures. 

Thank you all for the replies and advice thus far.