MaximumPC 2006 10

Ask the Doctor

68 MAXIMUMPC OCTOBER 2006

how 2 IMPROVING YOUR PC EXPERIENCE, ONE STEP AT A TIME

I had a PC some time back that produced

a “low buzz” like the one described in

“Catching a Buzz,” in your July column.

Well, it was really more like a “low buzz

from H-E-double-toothpicks,” if you know

what I mean. Anywho, I fi nally gave up

and called tech support (yeah, yeah, I’m

a geek failure), who had me double-click

the speaker icon in the system tray to see

if Mic Volume was muted or not. It seems

that if you don’t have a microphone

plugged in, and Mic Volume is not muted,

the audio pickup circuit will pick up noise

as you drag the cursor across the desk-

top. Talk about sensitive!

—John Steedley

SLI MIX-N-MATCH

I have an XFX GeForce 7900 GT with 256MB of

memory. The core is clocked at 520MHz and the

memory runs at 750MHz. I’d like to pair that with

an EVGA GeForce 7900 GT, but this card’s core

runs at only 500MHz (its memory is clocked at

750MHz, same as the XFX). Is it OK to run these

two cards together?

—George Shock

As long as you’re using Forceware release

80 or higher, you can mix and match any two

GeForce videocards based on the same GPU.

Each GPU and frame buffer can be clocked at a

different rate, and they can even have different-

size frame buffers. You must also have an SLI

motherboard, of course; but you already knew

that, right?

GOING WIDE

I recently bought this beefy 21-inch widescreen

display from Gateway. It’s equipped with a DVI-D con-

nection, but my videocard—a Radeon X700—has a

DVI-I port. I’ve been searching for a videocard with

DVI-D, but I can’t find one. Any advice?

—Joe De Luna

The only difference between DVI-I and DVI-D

connectors is that the former carries both ana-

log and digital signals. Five pins (two round

ones above and two below a broad flat pin)

on the left side of the connector carry analog

signals for connecting to an analog monitor.

The pins that carry digital information are

exactly the same on a DVI-I cable as they are

on a DVI-D cable, so your Radeon X700 should

work with that monitor. For best results, set the

videocard to the display’s native resolution. You

didn’t indicate the model number, but if it’s the

FPD2185W, that would be 1680x1050.

TIME SYNC

I’m having trouble connecting my Windows XP PC to

my Philips CRT HDTV. I bought an HDMI-to-DVI cable,

but I don’t get any picture when I hook up my PC to

the TV. I have an AGP version of nVidia’s GeForce

6600 GT with 128MB of memory, and I’m running

the latest Forceware drivers. Do I have the right

cable, or do I need a DVI-to-HDMI cable?

—Brett Walton

As long as you have a cable with a DVI connec-

tor on one end and an HDMI cable on the other,

you have the right cable. I suspect your problem

is either that your videocard is set to a resolu-

tion your monitor can’t display, or that it’s set

to a scan rate your monitor doesn’t understand.

Connect your computer to a computer monitor

and set its resolution to your TV’s native resolu-

tion. If your TV still won’t display a picture, you

might need to tweak the videocard’s scan rate.

Connect your PC to a computer monitor again

and go into the videocard’s display properties.

Click the Advanced Timing button and set the

horizontal and vertical frequencies to the cor-

rect values for your TV (these should be listed

in the owners manual). Warning: Setting the

incorrect values could permanently damage

your display.

SHAKE-N-BAKE

I recently moved and my computer was

jostled around a little. I didn’t think too

much of it, as I often take my PC to LAN

parties. When I first connected it at the

new place, it started fine but shut itself

off after a few minutes. I started it up a

second time, and the same thing hap-

pened after about 10 minutes. On the

third try, the system got as far as the

Windows loading

screen, where it stayed for

a couple minutes before

rebooting. I’ve reseated all

the cards in their slots and

double-checked all the connectors. What

else could it be?

—Ethan Jackson

You’ve already checked the most obvi-

ous possibilities, but you might also try

removing and re-installing your CPU’s

fan and heatsink. An overheating CPU

is one of the most common causes of

premature shutdown, so it could be that

the frequent moves have opened a gap

between the top of the processor and the

bottom of the heatsink. Use alcohol to

remove any residual thermal grease from

the heatsink and CPU, re-apply a small

amount of fresh material, and lock down

the heatsink again.

Troubleshooting noise in your PC?

Try muting your mic input if there’s no

microphone plugged into it.

nVidia allows you to create custom timings for

HDTV monitors, but consult your TV’s manual

before going down that path: Incorrect timings can

permanently damage your set.

If double, double, toil and trouble is an apt description of your PC’s

condition, seek the Doctor’s counsel. He’ll toss a little eye of newt

and toe of frog in his cauldron and whip up a curing spell for ye.

Email the [email protected].

SECOND OPINION