M5A78L-MX - no video from PCIE graphics cards, only from built-in

[Grabo]

Hi.

I recently acquired this rather cheap little matx board.
It shows an image and POSTs (and beeps once) if display is connected to the built-in graphics (VGA port).

I have two graphics cards that I've no way of verifying if they work - they did the last time I tried them, which was some time ago. Here's what happens when I connect them:

1. HD4870: (DVI -> VGA adapter) - No video, no beep at all from PC speaker, everything appears to power up. None of the four lights at the back of the graph card is lit. The graphics card fan is spinning.

2. Asus EAX 1550 silent: (VGA) - No video, normal POST beep from PC speaker. If display VGA cable is connected to the built-in graphics VGA port (while the 1550 is inserted) the image appears on the display.

I've reset the BIOS via the pins on the mobo and updated it. The #1 graphics route is in the BIOS set to PCIE-16x.

Without further testing, can I conclude anything else than that likely the PCIE16x slot on the mobo is cursed? The machine goes into a coma with the HD4870 connected (no PC speaker beep even) and acts as if the 1550 isn't even there when it is in fact connected.

Why can't it beep that there's an issue with the graphics card, as per http://support.asus.com/Troubleshoo...0LX&s=24&hashedid=5YkHeMJXc3aijWxY&os=&no=978 ?

Any comment is welcome.

 

[superccs]

What CPU do you have in it.... Maybe the Mobo needs a BIOS flash.

 

[Grabo]

I've flashed it to the latest version, and reset its settings via the jumper on the board.
The CPU is a Phenom II X3 710 and it is recognized. Everything points to the system being viable if run via the built-in graphics.

How often do PCIE6x slots go(or come) defect? :/

 

[THRiLL KiLL]

check the bios settings.

Some motherboards you can have an option to boot only from the on board.

so i would change the display order or try disabling the onboard video

 

[Grabo]

You can set graphics boot priority but I don't think you can disable the built-in graphics. I've tried different priorities with no different results.

Anyway, I have an incoming upgrade - a 6850 - and since chances are slim that it will be DOA, it'll tell whether it's the PSU or motherboard or whether it's the two other graphics cards that are faulty. (Let's just hope that neither the mobo nor the PSU has turned into a grapics card killer)

I don't think it's a mobo settings issue for I had a similiar mATX with built-in graphics and adding an adapter to the PCIE16x slot automatically overrode the built-in, something I'd consider expected default behaviour. Indeed, the graphics boot sequence suggests so.

 

[Grabo]

To conclude: Yep, it seems to have been the two graphics cards I tried. I was fairly certain something was up with the HD4870 seeing as how there was no PC speaker beep whatsoever with it installed but it also seemed somewhat unlikely both it and the other card would be broken.

Nevertheless, video goes through the 6850 immediately.