MSi GT780DX: Upgraded to GTX675m, HDMI doesn't function anymore

So I replaced the GTX570m in my MSi GT780DX to a Dell GTX675m and everything works perfectly EXCEPT for the HDMI port. VGA works fine. But the thing is, there's never any sort of error message or notification, no "Device not recognized", etc. Anything plugged into the port just won't show up. No "You plugged something in! : D" sound effects, so it's more like it's just pretending it's not there. Before I give my hypothesis, here's what I've done:

First off, I have Windows 7. In preperation for the GTX675m, I removed the graphic drivers (using "add/remove programs" and "Driver Sweeper", carefully following an instruction set, so nothing gets unnecessarily removed) for the GTX570m, opened the laptop, cleaned and repasted where necessary, installed the card, booted the laptop, installed the appropriate drivers, rebooted. Tried out some games on it and as expected, it throttles constantly, but it functions! Anyway, I hesitantly proceeded to follow Xonar's instructions to utilize his modded bios (retrieved the appropriate version, made a bootable flash-drive, etc). Works perfectly. Installed and activated ThrottleStop to stop throttling (hurr). That works too! :3 By then I noticed an issue with my HDMI port. I can't recall all of the methods I attempted to get it to at least realize that it exists... Reinstalled graphic drivers, went through Nvidia control panel and tried everything necessary there, tried Fn+F2 (for this particular model, that's the "connect to a projector or external display" function). Tried different monitors, I know the cable works because I still use it for other things, I searched for it in Device Manager, tried refreshing for hardware changes, changed some seemingly relevant options in the now extensive bios. One of which was enabling on-board graphics, which I knew would most likely result in a blank screen. It did, so I looked up a picture of the bios to find which function key restored defaults. Blind-booted into bios and restored defaults, works fine. ... I'm sure I tried more, but I can't remember.

I suspect it has to do with the new Bios options and I just don't know for sure what it is. I'd rather not kill my computer or spend hours looking up what all the abbreviations stand for just to find it's not the solution. No, I haven't flashed the Vbios, GPU-Z will even tell me that the sub-vendor is Dell. I very much doubt that's necessary anyway. I really don't want to get into anything else risky unless somebody reputable and very knowledgeable on the subject tells me that it's definitely the solution.

Thanks in advance for any help! I REALLY hope to get this fixed. VGA streams 1920-1080 but doesn't look as good and I'm down a display.

 

Might be an issue with the dell card and vbios in the msi machine.

 

Yeah, as time goes on I suspect that might be the case. But I really have no experience with Vbios or it's full purpose as opposed to the MoBo Bios. There are a lot of options in the new Bios I installed, though. Some things were already disabled and RAID was enabled, so the options were already not set up correctly for my system to begin with, which is why I was thinking there's just another option, or series of options, to enable HDMI. I was hoping that there's someone here who's used the same unlocked bios and knows a lot more about it than I do. : P

 

Which driver do you have installed?
edited the .inf file?

 

I didn't personally edit anything; just followed instructions and used the modded bios. As for graphic drivers, I just installed the most up-to-date Nvidia drivers from their site, just like you normally would.

I don't feel like I answered your question the way you wanted. : P

 

I guess nobody really knows?

 

It could be an Optimus thing.

If so, flashing it over to an MSI 580M vBIOS may help.

 

Hmm... If it was an optimus thing, I'd be having a lot more issues though, wouldn't I? Or I could disable optimus in the now extended bios options, if it is an option. My computer doesn't actually have optimus though, of course. Which is why I think it'd be causing a lot more issues if it was somehow enabled in the bios.

Anyway, I'm trying not to flash anything else unless I have to, although it seems like my last option unless somebody has a better idea of what's really going on. I have no experience dealing with Vbios, but I have plenty of common sense. Any experienced advice is still very much welcome, though. Thanks for all the replies so far. :3

 

With Optimus, the IGP handles HDMI-output. So since the 675M was released in Optimus-enabled laptops, I was thinking the vBIOS could be missing something found in the older cards' vBIOS that gets the discrete GPU to handle HDMI-output.

 

As far as I know, the GT780DX does not yet support Optimus, as well as the MSI GT683DX (15.6 "version of the GT780DX with the same motherboard).

I would also MSI GTX580M/GTX675M VBIOS flash on the card, then everything should work out fine.

 

Exact same symptoms back in 2010 when people using MSI AMD 5870M vBIOS to flash on Asus G73JH's 5870M. the vBIOS are not compatible with system BIOS, they don't communicate with each other.

 

It's to do with the HDCP which is why analogue outputs work.

 

Alright, I finally stopped being lazy and flashed my GPU with SVl7's .92v MSI GTX 675m VBIOS and everything works just fine now! I know this is an old issue now, but I just wanted to thank everyone for their help. : D And I'll hand out rep where I can.

 

Interesting, it must have the right signature in it, well enjoy.