Question unrecognized ati radeon hd 5450 low profile in a m2n68-la mobo

[Minhgko]

Greetings everyone!

Long time reader, first time posting, so let me start by thanking the community for the all tips and tricks I've learnt here!

After having a problem with my laptop, I've been offered a desktop PC that was not used anymore. It's a HP G5405pt (the motherboard says "m2n68-la"), and it had only integrated graphics, and even though I just need a PC to do video-calls (working and attending online school sessions), I would like to play some games (like Wow, Hearthstone, or Minecraft), even if in the lowest quality. After confirming that this PC had an unused PCIe 16 slot, I found out that there was a guy nearby selling an ATI Radeon HD 5450 Low Profile, so I just went for it.

As the graphics card doesn't need a power cable, I just inserted it in the correct slot, connected the monitor to the VGA port on the card, and then turned the PC on. The monitor didn't show anything, so I connected it to the onboard VGA port, and realized the output was still going through there.
Investigating the BIOS (actually there wasn't a lot to investigate), I only found one option relating to graphics, the primary graphics setting, which had the PCI option selected. I changed it to PCIe, saved and rebooted, but there was no change: output was still through the onboard VGA port.
I don't think the PC is recognizing at all that it has a graphics card.

I tried pulling it out and putting it back in, confirming it was placed correctly, but that didn't seem to be the issue.
I've thought about BIOS updates, but the only files I can find online have versions lower than my current version.

Notes:

• I never see the POST or the BIOS screens through the graphics card, only through the onboard VGA, so I don't think my problem has to do with Windows management of the card.
• The graphics card gets hot even though it does not produce any output.

So my questions are:

1. Are there any procedures that I'm unaware of? If so, what are those procedures?
2. Is there any incompatibility between this mobo and this graphics card?
3. As a really last resort, if it turns out I need another graphics card, could you recommend one that works with this mobo?

The PC has these specs:
Motherboard: m2n68-la (Pegatron Corporation, 2A99)
CPU: AMD Athlon II X2 260
PSU: 500W (LL-PS-500)
RAM: 1x 4Gb DDR3
OS: Windows 7 Ultimate, 64 bits

Thanks in advance, everyone.
Keep up the good work! =)

M.

 

[Minhgko]

[UPDATE]
The seller sent me another HD5450, and it works, but this one crashes in the middle of some games and in the middle of Zoom calls (sometimes it says the driver crashed and recovered, other times it just freezes the PC and I have to reboot the PC by pressing the power button for 5 seconds).

Is it the driver? Is it the graphics card? I started monitoring the temperatures, and it goes to 85ºC while playing a game in windowed mode (it didn't crash while I was monitoring it, though), but rests around 60ºC while the PC is idle.

Maybe I should check the thermal paste too?

Thanks in advance.
M.