DVI -VGA ADAPTER QUESTION

I need a converter to enable me to connect my DVI PC to my VGA
monitor. Looks like the DVI is 18-pin whereas the converters I see
are all 24-pin. Should the latter work since both wud fit my PC DVI
port? If not, can someone point me to the right converter?

Thanks

JW

On 12/6/2016 5:31 PM, wrote:
I need a converter to enable me to connect my DVI PC to my VGA
monitor. Looks like the DVI is 18-pin whereas the converters I see
are all 24-pin. Should the latter work since both wud fit my PC DVI
port? If not, can someone point me to the right converter?

Thanks

JW


Determine which type of DVI port you have and find an online converter
for it.

See He https://en.wikipedia.org/wiki/Digital_Visual_Interface

and he https://en.wikipedia.org/wiki/DMS-59

On Tue, 6 Dec 2016 17:38:33 -0600, "." wrote:

On 12/6/2016 5:31 PM, wrote:
I need a converter to enable me to connect my DVI PC to my VGA
monitor. Looks like the DVI is 18-pin whereas the converters I see
are all 24-pin. Should the latter work since both wud fit my PC DVI
port? If not, can someone point me to the right converter?

Thanks

JW


Determine which type of DVI port you have and find an online converter
for it.

See He https://en.wikipedia.org/wiki/Digital_Visual_Interface

and he https://en.wikipedia.org/wiki/DMS-59


ok

My PC appears to be DVI-D dual-link.
It connects to my monitor just fine with a DVI cable having a DVI-D
single link ends.
My PC also has a VGA port. It connects to my monitorand displays just
fine with a VGA cable. So I know the monitor handles both VGA or DVI.

I have a converter with a DVI-D dual-link that plugs into PC just
fine. It has a 15-pin connection on other end that connects to my VGA
cable to monitor just fine. No surprise. But no signal. Big
surprise.

What do I need?

JW

On 12/6/2016 6:24 PM, wrote:
On Tue, 6 Dec 2016 17:38:33 -0600, "." wrote:

On 12/6/2016 5:31 PM, wrote:
I need a converter to enable me to connect my DVI PC to my VGA
monitor. Looks like the DVI is 18-pin whereas the converters I see
are all 24-pin. Should the latter work since both wud fit my PC DVI
port? If not, can someone point me to the right converter?

Thanks

JW

Determine which type of DVI port you have and find an online converter
for it.

See He https://en.wikipedia.org/wiki/Digital_Visual_Interface

and he https://en.wikipedia.org/wiki/DMS-59

ok

My PC appears to be DVI-D dual-link.
It connects to my monitor just fine with a DVI cable having a DVI-D
single link ends.
My PC also has a VGA port. It connects to my monitorand displays just
fine with a VGA cable. So I know the monitor handles both VGA or DVI.

I have a converter with a DVI-D dual-link that plugs into PC just
fine. It has a 15-pin connection on other end that connects to my VGA
cable to monitor just fine. No surprise. But no signal. Big
surprise.

What do I need?

JW

StarTech DVI2VGAE DVI-D to VGA Active Adapter Converter Cable
available everywhere - from Amazon to Walmart.

wrote:
On Tue, 6 Dec 2016 17:38:33 -0600, "." wrote:

On 12/6/2016 5:31 PM, wrote:
I need a converter to enable me to connect my DVI PC to my VGA
monitor. Looks like the DVI is 18-pin whereas the converters I see
are all 24-pin. Should the latter work since both wud fit my PC DVI
port? If not, can someone point me to the right converter?

Thanks

JW

Determine which type of DVI port you have and find an online converter
for it.

See He https://en.wikipedia.org/wiki/Digital_Visual_Interface

and he https://en.wikipedia.org/wiki/DMS-59


ok

My PC appears to be DVI-D dual-link.
It connects to my monitor just fine with a DVI cable having a DVI-D
single link ends.
My PC also has a VGA port. It connects to my monitorand displays just
fine with a VGA cable. So I know the monitor handles both VGA or DVI.

I have a converter with a DVI-D dual-link that plugs into PC just
fine. It has a 15-pin connection on other end that connects to my VGA
cable to monitor just fine. No surprise. But no signal. Big
surprise.

What do I need?

JW

https://en.wikipedia.org/wiki/Digital_Visual_Interface

Look at the pinout

C1 Red
C2 Green
C3 Blue
C4 HSYNC
Pin8 VSYNC

Now look at the connector pictures. The DVI-D ones
are missing C1/C2/C3/C4. That means a DVI-D,
you cannot use a passive DVI-I to VGA adapter.

https://upload.wikimedia.org/wikiped..._Types.svg.png

An *active* connector on the other hand,
has a chip inside it. It converts a DVI
digital stream, into analog signals such
as the RGBHV mentioned above.

A passive adapter costs $5 and passes
the RGBHV from C1-C4 and friends, to the
15 pin VGA connector.

An active adapter costs $30-$100, needs a source
of power like +5V, and converts the digital
color signals into analog color signals.
And that drives the VGA 15 pin.

StarTech DVI2VGAE DVI-D to VGA (Active)
http://www.newegg.com/Product/Produc...82E16812400402

You can see that active adapter doesn't connect
to C1-C4 as the source doesn't have the pins. Instead,
it converts a single link DVI-D signal to VGA. It
will not connect to the second link.

https://sgcdn.startech.com/005329/me...2VGAE.main.jpg

The product comes with a USB cable. That connects
+5VSB from the computer, to the back of the
square converter.

https://sgcdn.startech.com/005329/me...I2VGAE.bom.jpg

And the power hole on the back of the square converter
is here.

https://sgcdn.startech.com/005329/me...DVI2VGAE.D.jpg

The Newegg price is pretty good.

There's no reason for the adapter to support
HDCP. The VGA signal should be every bit
as functional as the VGA signal on the
real computer. Within the resolution
limits of a single link DVI-D source.
(Real video cards might do 2048 or 2560,
but the adapter in this case does 1920 max.)

Paul

On Wed, 07 Dec 2016 00:27:08 -0500, Paul
wrote:

wrote:
On Tue, 6 Dec 2016 17:38:33 -0600, "." wrote:

On 12/6/2016 5:31 PM, wrote:
I need a converter to enable me to connect my DVI PC to my VGA
monitor. Looks like the DVI is 18-pin whereas the converters I see
are all 24-pin. Should the latter work since both wud fit my PC DVI
port? If not, can someone point me to the right converter?

Thanks

JW

Determine which type of DVI port you have and find an online converter
for it.

See He https://en.wikipedia.org/wiki/Digital_Visual_Interface

and he https://en.wikipedia.org/wiki/DMS-59


ok

My PC appears to be DVI-D dual-link.
It connects to my monitor just fine with a DVI cable having a DVI-D
single link ends.
My PC also has a VGA port. It connects to my monitorand displays just
fine with a VGA cable. So I know the monitor handles both VGA or DVI.

I have a converter with a DVI-D dual-link that plugs into PC just
fine. It has a 15-pin connection on other end that connects to my VGA
cable to monitor just fine. No surprise. But no signal. Big
surprise.

What do I need?

JW

https://en.wikipedia.org/wiki/Digital_Visual_Interface

Look at the pinout

C1 Red
C2 Green
C3 Blue
C4 HSYNC
Pin8 VSYNC

Now look at the connector pictures. The DVI-D ones
are missing C1/C2/C3/C4. That means a DVI-D,
you cannot use a passive DVI-I to VGA adapter.

https://upload.wikimedia.org/wikiped..._Types.svg.png

An *active* connector on the other hand,
has a chip inside it. It converts a DVI
digital stream, into analog signals such
as the RGBHV mentioned above.

A passive adapter costs $5 and passes
the RGBHV from C1-C4 and friends, to the
15 pin VGA connector.

An active adapter costs $30-$100, needs a source
of power like +5V, and converts the digital
color signals into analog color signals.
And that drives the VGA 15 pin.

StarTech DVI2VGAE DVI-D to VGA (Active)
http://www.newegg.com/Product/Produc...82E16812400402

You can see that active adapter doesn't connect
to C1-C4 as the source doesn't have the pins. Instead,
it converts a single link DVI-D signal to VGA. It
will not connect to the second link.

https://sgcdn.startech.com/005329/me...2VGAE.main.jpg

The product comes with a USB cable. That connects
+5VSB from the computer, to the back of the
square converter.

https://sgcdn.startech.com/005329/me...I2VGAE.bom.jpg

And the power hole on the back of the square converter
is here.

https://sgcdn.startech.com/005329/me...DVI2VGAE.D.jpg

The Newegg price is pretty good.

There's no reason for the adapter to support
HDCP. The VGA signal should be every bit
as functional as the VGA signal on the
real computer. Within the resolution
limits of a single link DVI-D source.
(Real video cards might do 2048 or 2560,
but the adapter in this case does 1920 max.)

Paul

Thanks for tuning in Paul. You're always there and I appreciate it.
I wondered why the two DVI-D connectors wouldn't work since they would
connect. It became obvious that the pinouts were different.

The truth of the matter is - this was all for my SIL, whose old VGA
machine broke down. He does not live close. I have an old PC I
don't need, so I thought to give it to him. It works fine for me,
but it is connected to my monitor via DVI cable. Its mobo DVI and VGA
path had long since failed, and I had replaced that with a DVI/PCI
card. So, although my monitor has both DVI and VGA, and will run on
both, he cannot run it VGA without a converter (or another PCI card.
I guess). And- my SIL's monitor only has VGA anyway. And of course,
he has a VGA cable. Hence my thought to come up with a converter.

Have to buy one for a Christmas present, huh?

Damn! I did not expect such a thing to be so expensive.

Thanks again.

JW

All of these

StarTech DVI2VGAE DVI-D to VGA (Active)
http://www.newegg.com/Product/Produc...82E16812400402

http://www.ebay.com/itm/DVI-to-VGA-D...AOSwn7JYCTe ~



would require a USB cable for power source, right?

JW

wrote:
All of these

StarTech DVI2VGAE DVI-D to VGA (Active)
http://www.newegg.com/Product/Produc...82E16812400402

http://www.ebay.com/itm/DVI-to-VGA-D...AOSwn7JYCTe ~



would require a USB cable for power source, right?

JW

No, that one is probably more evil.

If you check the DVI article on Wikipedia,
the connector does have a power pin. But usually
the purpose of that pin, is to power the EDID serial
eeprom inside the monitor.

http://electronics.stackexchange.com...-vga-connector

"Per the DVI spec R1.0, the "+5V signal is required
in a DVI compliant system - the power pin must be able
to supply a minimum of 55mA and the monitor may not
draw more than 50mA."
"

Then the question becomes, whether the video card can source
sufficient current to keep the active converter powered.

The advantage of the USB powered converter, is you get
at least 500mA of potential power.

I don't have a datasheet for those converters, so can't
even begin to guess what an appropriate estimate would be.

Paul

On Wed, 07 Dec 2016 08:23:40 -0500, Paul
wrote:

wrote:
All of these

StarTech DVI2VGAE DVI-D to VGA (Active)
http://www.newegg.com/Product/Produc...82E16812400402

http://www.ebay.com/itm/DVI-to-VGA-D...AOSwn7JYCTe ~



would require a USB cable for power source, right?

JW

No, that one is probably more evil.

If you check the DVI article on Wikipedia,
the connector does have a power pin. But usually
the purpose of that pin, is to power the EDID serial
eeprom inside the monitor.

http://electronics.stackexchange.com...-vga-connector

"Per the DVI spec R1.0, the "+5V signal is required
in a DVI compliant system - the power pin must be able
to supply a minimum of 55mA and the monitor may not
draw more than 50mA."
"

Then the question becomes, whether the video card can source
sufficient current to keep the active converter powered.

The advantage of the USB powered converter, is you get
at least 500mA of potential power.

I don't have a datasheet for those converters, so can't
even begin to guess what an appropriate estimate would be.

Paul

Thanks Paul.
JW