[mythtv-users] OT: dead motherboard or video card?

[Brian Wood]

On Wednesday, June 16, 2010 10:34:57 am Greg Woods wrote:
> On Wed, 2010-06-16 at 08:16 -0600, Brian Wood wrote:
> > On Wednesday, June 16, 2010 08:09:32 am bhaskins at chartermi.net wrote:
> > > Get a live cd of any recent popular distro, boot up from that and
> > > compare that to what you now have.
> > 
> > Probably the best way to go, short of replacing the mobo.
> 
> I tried booting from the F13 install DVD. I see the initial grub screen,
> but shortly after that, the monitor puts up a warning that it cannot
> display and I never see anaconda, just a black screen. That never
> happened before either.
> 
> > The problem may be with the replacement power supply. If it has
> > insufficient capacity, odd things can happen. Video cards draw a lot of
> > current.
> 
> It is larger than the old one (650W vs. 450W). So while I can't rule out
> a brand-new power supply somehow being defective, it seems unlikely and
> I'm pretty sure it has plenty of capacity.

"Infant Mortality" happens with new devices. If I had to pick between a PSU that had been running a while and a brand new 
one, I'd suspect the new one more.

The power rating on a PSU can also be suspect, an aggregate total does not tell you the rated current on each rail. I've 
seen PSUs rated "600 watts" or more that couldn't support even a basic machine.

You'd think the "brand name" units might be better than the no-names, but this has not been my experience. The best way I 
have found to rate a PSU is to pick it up, if it's light as a feather it's probably crap, good quality inductors are 
fairly heavy.

The PSU "testers" sold for under $50 are not worth a hoot, they do not load the supply at all, and will show up only a 
total failure of a rail.


> I might try this; I could unplug all the SATA/recording drives and try
> to boot from the IDE DVD again.
> 
> I also had my hardware friend suggest trying the onboard video chip;
> frankly, I had forgotten that it had one (it's not VDPAU-capable so I
> had to disable it in the BIOS and use a PCI-E video card).
> 
> Come to think of it, the chip being found by lspci might be the onboard
> one (also Nvidia). It may be that the PCI-E slot simply doesn't work any
> more. I'll try re-enabling the onboard chip and see what happens.

If your monitor is plugged into the video card, then it is doing something, at least putting out console type messages.

Though you are correct, you have to be careful which one you're seeing with lspci.

Plugging your monitor into the mobo's video connector and removing the video card is probably a good way to at least get a 
start on the problem.

> 
> > Also remember that any time you open the case and put your hands inside
> > you run the risk of loosening a cable or connector, or doing other
> > unintended things. I'm not denigrating your technical ability, I speak
> > from sad experience.
> 
> That is a valid point, but I have carefully checked everything. All the
> drives are found by the BIOS. I'm not sure what kind of connection could
> be wrong that would cause only the video card to malfunction; it does
> not have a power connection other than from the PCI-E bus.


Even bumping and loosening a card can cause problems. I generally remove all cards and re-seat them (not just push them 
down) to make sure everything's seated well.