[Pc_Support] No CD-ROM power, no POST?

[Bryan J. Smith]

Jason Boxman <jasonb at edseek.com> wrote:
> So, I go to install my new 6600GT.  No go.
> It boots up with corrupt graphics at the BIOS screen.

Does it have a 4-pin Molex connector on the card end opposite
of the bracket?  If so, plug in a Molex connector.

The AGP slot is only capable of delivering 25-50W.
The AGP Pro (rare) is able to deliver 50-100W.

Both the card _and_ mainboard must be AGP Pro.
Since this is rare (typically only Quadros), you need the
Molex.

> Well, after removing all my expansion cards and such, I
> discover the reason it does nothing at power no, no beep,
> no POST, nothing, without a video card installed, is
> because the CD-ROM is plugged into the motherboard, but
> the power connector for the CD-ROM is not plugged in.
> Eh?

The POST will be interrupted because the ATA channel is in
use, attempting to flip gates with +3.3/5V signals, but the
PCB on the drive isn't being powered, so the board doesn't
respond.  It never gets out of a transient phase, so the
system never boots.

The PC BIOS and ATA logic is _really_dumb_.  ATA relies on
the Integrated Drive Electronics (IDE) and if it detects a
drive is plugged in, but the IDE doesn't respond (like in
your case, no power), many BIOS POST routines will just hang.

Same issue when people used to flip their ATA connector
orientation.

> That's the number one reason I absolutely had screwing
> around with my boxes.  Something always goofs up.  Always.
> And it seems it always costs me money.  Sigh.
> I'll have to try the 6600GT in my other AGP box and see if
> it works okay or not.
> Meanwhile, time to put my expansion cards back in, again.

Don't forget the Molex connector.

*ALSO*, what is your mainboard?
It could be a voltage issue.

AGP 2.0 (4x) is 1.5/3.3V
AGP 3.0 (8x) is 0.8/1.5V

Many AGP 3.0 (8x) video cards are no longer 3.3V tolerance,
and if your mainboard can't deliever 1.5V to the AGP, you're
SOL.



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