Author Topic: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).  (Read 69580 times)

BOBALONG

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DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« on: December 16, 2005, 02:36:04 »
CAN ANYONE HELP??      I HAVE AN ADAPTER THAT HAS BEEN BROKEN IN TWO AND HAVE FOUND THE RIGHT PINOUTS FOR EACH PLUG FACE,
BUT IM STILL NOT SURE OF THE SOLDER CONNECTIONS.......CAN ANYONE SIMPLIFY THIS FOR ME ,I.E.  A DIAGRAM WOULD BE GOOD.

CARD- ATI RADEON RX9250 DUAL HEAD.

ADAPTER- DVI ANALOG TO STANDARD VGA MONITOR.

ITS JUST A GENDER CHANGER! BUT I NEED TO KNOW "WHATS INSIDE"[/img]

Anonymous

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DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #1 on: December 16, 2005, 18:41:45 »
just simpl  check the dvi connector  to right side you look + type pins this is a analog signal   c1,c2,c3,c4,&c5  & dvi connector pin 8
 c1===red
c2=====green
c3=====blue
c4=====h syinc
c5====== all gnd
pin 8===== v synic

BOBALONG

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DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #2 on: December 16, 2005, 23:40:41 »
MAD...your the best Bro!

It was a simple question...just to help me figure out the pinouts,I plan to
make a diagram(becuase I wasnt able to find one anywhere)..and submit
it to this site...it maybe usefull to others.

Thanx again for your help,...CHEERES GEE.

BOBALONG

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RE-ADAPTER(DVI/VGA)
« Reply #3 on: December 17, 2005, 23:31:33 »
Thankyou again for the help.....everything works out same as my pinouts,
but I still have another 5 wires hanging out the back of dvi plug.

This is what I have so far,

DVI >>>>   TO  >>>>>>   VGA.

C1-analog red ------------>1-red video          
C2-analog green --------->2-green video
C3-analog blue ----------->3-blue video
C4-analog horz sync ----->13-hsync or csync
C5-analog ground -------->*all ground*
8-analog vert sync ------->14-vsync
 

   ?????Any help on these would be V helpfull.

6-DDC clock                      ?
7-DDC data                       ?
14-  +5V power                 ?  
15- gnd                             ?
16- hot plug detect             ?     :D

Anonymous

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Re: RE-ADAPTER(DVI/VGA)
« Reply #4 on: March 18, 2006, 07:54:47 »
Quote from: "BOBALONG"

but I still have another 5 wires hanging out the back of dvi plug.

This is what I have so far,

DVI >>>>   TO  >>>>>>   VGA.

C1-analog red ------------>1-red video          
C2-analog green --------->2-green video
C3-analog blue ----------->3-blue video
C4-analog horz sync ----->13-hsync or csync
C5-analog ground -------->*all ground*
8-analog vert sync ------->14-vsync
 

   ?????Any help on these would be V helpfull.

6-DDC clock                      ?
7-DDC data                       ?
14-  +5V power                 ?  
15- gnd                             ?
16- hot plug detect             ?     :D


From the info on this site and a bit of googling,
plus some dissection of my broken DVI/VGA adaptor
(the reason I'm here):

VGA pins are VESA DDC2 update spec:

DVI-6 DDC clock <> VGA-15-SCLK
DVI-7 DDC data <> VGA-12-SDATA
DVI-14-+5V pwr <> VGA-9-+5V
DVI-15-GND <> VGA-5 and 10 GND and SyncGND
DVI-16-Hotplug Detect <> ???

Note that the original VGA standard used pin 9 as a no-connect key.  That entire middle row, save for pin 9, is grounds, along with pin 5 on the end of the top row.  The +5V still isn't commonly used, apparently, but can be handy as a power source for various adapters and is part of both the VESA DDC2 and DVI standards.  You will likely be fine without it, but that's what it is, if you need it or if you want to be fully compatible.

The DDC clock and data pins will be necessary for plug and play, but manual configuration should be possible without them.  Just be sure to plug in all the correct clock and resolution values, or if you go testing, don't let it run for long in bad video modes or you can damage your equipment.  (A second or two of testing should be fine, however, as long as the voltages and the like remain video standard -- don't go testing it plugged into the power mains or the like! <g>)

Technically, VGA pins 6,7,8 are the RGB grounds and should be connected to DVI-C5.  VGA pins 5,10 are general ground and sync ground and should be connected to DVI-15.  At least, that's how it was on my broken adapter.  Note that the RGB operating voltages are different than the TTL signaling voltages on the other lines, so keeping the two grounds separate might be wise. Anyway, with VGA pin 9, +5V power, between them, it can be easier just to run separate conductors for the two, even if they could be jumpered together.

That  leaves hot-plug detect, DVI-16, as the only wire still hanging at this end.  Unfortunately, I can't be sure whether it should connect to VGA-4 (marked as RESERVED on VESA DDC2, ID2 on the original VGA) or VGA-11 (ID0 on original VGA).  Note that ID1 and ID3 on the original VGA are SCLK and SDATA, pins VGA-15 and 12, on DDC2, leaving VGA-4 and 11, ID0 and ID2/RESERVED as the only unaccounted for pins.  RESERVED on VGA-4might be taken to mean unused at present, which would mean the connection is to VGA-11.  OTOH, RESERVED might have been updated to hot-plug-detect in the DVI VGA-compatibility version, so I really don't know.

If I can't find anything definitive on DVI-16, I'll probably trial and error it.  Even direct-connecting it to either +5v hot or GND shouldn't be harmful, as everything but the RGB was designed to work with TTL anyway.  However, testing with a meter would likely be wise first, just in case.

Good luck!

Duncan

Anonymous

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Re: RE-ADAPTER(DVI/VGA)
« Reply #5 on: March 18, 2006, 12:57:00 »
Quote from: "Anon/Duncan/I"

DVI-16-Hotplug Detect <> ???

That  leaves hot-plug detect, DVI-16, as the only wire still hanging at this end.  Unfortunately, I can't be sure whether it should connect to VGA-4 (marked as RESERVED on VESA DDC2, ID2 on the original VGA) or VGA-11 (ID0 on original VGA).


OK, some more info on DVI-16-Hotplug-Detect.

The DVI spec can be downloaded for free from the Digital Display Working Group (DDWG) website (~1.2MB PDF, you'll have to select and paste in the address bar as it won't let guests post links, and who knows if I'll be here again, so I'm not going to register): ddwg.org/lib/dvi_10.pdf

Starting on ~pg 16 of that document, it lists the requirements for Hotplug-Detect (HPD).  Briefly, it comes down to this:

HPD is a Monitor to Computer signal.  < .4V monitor side, .8V computer side, is to be interpreted as no EDID/DDC compliant display present.  > 2.4V Monitor side, 2.0V computer side, is to mean an EDID/DDC capable display is present.  Monitor controls the level.  5V signaling levels are appropriate.

The spec didn't specify fully what action software should take to the hotplug event (HPD switching levels, indicating the plug or unplug of a compliant monitor), but did to the extent that if a compliant  monitor comes online, the signal should be activated, and if it goes offline, the signal must be terminated within 1 minute.  It didn't say, but this would appear to refer to the digital signal.

Both of the monitors I have handy here ground both VGA pins 4 and 11.  With pin 12 open, that would be  interpreted on the original VGA spec as Color monitor that can display 1024x768.  Of course, as mentioned upthread, DDC2 compliant connectors  have changed that.  VGA-4 is DDC-Reserved, and I found one mention (not well supported) that VGA-11 is DDC-ClkReturn.

While I still can't say for sure where that DVI-16 connected in the broken adapter of mine, the upshot of the above appears to be that for VGA adapter purposes,  DVI-16-HPD should be grounded, as the whole purpose is to use the analog signal from the DVI-I, not the digital signal.   It would further appear that today's monitors apparently ground both VGA-4 and 11, so that  grounding will appear in either case.

OTOH, from my googling, it was obvious that various video cards react to DVI-HPD in different ways.  Most seem to ignore it, while some do indeed keep the digital signal off if it's not high.  Also note that here, the xorg log (Linux) indicated that it could get DDC data from the monitor connected to the real VGA connector, but not the one connected thru the DVI/VGA adapter.  This is on a Radeon 9250 using the xorg native open source drivers, not ATI's proprietaryware closed drivers.  I've not experimented yet, but it's possible that forcing DVI-16-HPD high would allow the DDC detection to proceed, and that  it would then detect an analog monitor on the DVI-I connector and activate that, deactivating the digital.  Forcing it high could be accomplished by hard-wiring the upthread mentioned +5V to HPD, preferably thru a current-limiting resistor.

So... it should be safe to experiment with HPD forced high, or grounded, either one.  VGA monitors appear to ground it, regardless of whether it's supposed to connect to VGA-4 or VGA-11.  However, forcing it high could mean better automated detection of what's there.  OTOH, it may  have undesirable side effects such as disabling the analog signal.  Effects are likely to be somewhat video card dependent, variable from model to model.

Duncan

Jackey

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #6 on: March 25, 2009, 23:58:58 »
I would like to make a cable for Dual Link DVI-D to Analog VGA for me to connect DVI LCD to VGA port of the PC, any idea?

santy

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #7 on: May 20, 2009, 23:03:17 »
Hello, you can't do it, because you have DVI-D, and it only has digital signals, to do so, you need a DVI-I (Supports analog and digital signals), or DVI-A (only analog signals), if you wan't to do a cable, google DVI PINOUTS.
GOOD LUCK!!

psc

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #8 on: February 06, 2010, 12:35:54 »
i want to pin out details og dvi-d to VGA cable connection
Please help me

Roytech

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #9 on: February 24, 2010, 01:10:18 »
DVI-D to VGA is not possible with just connecting wires on the pins, it needs a DVI to VGA scalar converter

Bladze

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #10 on: March 09, 2010, 09:33:11 »
This may be a little late, but from what I can find the conversion goes something like this:

VGA                  DVI
1 Red                C1
2 Green             C2
3 Blue               C3
4 Monitor ID-2    Open
5 Ground           C5
6 Red Ground     C5
7 Green Ground  C5
8 Blue Ground    C5
9 KEY               Open
10 Sync Ground  C5
11 Monitor ID-1  Open
12 Monitor ID-0  6
13 H-Sync         C4
14 V-Sync         8
15 Reserved (?) 7

I found a few different descriptions if VGA pins 11, 12, and 15, so this is a best (educated) guess from what I have found.

EricJames

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #11 on: March 10, 2010, 06:54:41 »
 Hope this helps
C1-analog red ---1-red video          
C2-analog green ---2-green video
C3-analog blue ---3-blue video
C4-analog horz sync ---13-hsync or csync
C5-analog ground ---all ground
8-analog vert sync ---14-vsync
« Last Edit: March 11, 2010, 12:42:28 by admin »

Joshtaylor

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #12 on: March 11, 2010, 09:05:41 »
Technically, VGA pins 6,7,8 are the RGB grounds and should be connected to DVI-C5.  VGA pins 5,10 are general ground and sync ground and should be connected to DVI-15.
« Last Edit: March 11, 2010, 12:42:37 by admin »

jmk3r

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #13 on: October 24, 2010, 09:07:03 »
After I dissected my cable wich i use to conect a vga card to dvi port on my monitor the pinouts are:
VGA                  DVI
1 Red                 C1
2 Green              C2
3 Blue                C3
4 Monitor ID-2     Open
5 Ground            C5
6 Red Ground      C5
7 Green Ground   C5
8 Blue Ground     C5
9 KEY                14 and 16
10 Sync Ground   15
11 Monitor ID-0   Open
12 Monitor ID-1   7
13 H-Sync          C4
14 V-Sync          8
15 ID3               6
I Hope this helps.

Ben

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Re: DVI-A TO VGA ADAPTER PINOUTS(WIRING DIAGRAM).
« Reply #14 on: October 25, 2010, 08:07:06 »
Is there a difference between the adaptor used to convert:
* DVI output on a PC to a VGA Input on a monitor/tv
vs
* VGA output on a PC to DVI Input on a monitor/tv

I understand DVI can send/receive both Analogue and Digital Signals both in the same cable.
Some LCD monitors and TVs accept Analogue in via DVI.

So based on this is there a difference between me connecting

PC (VGA) > VGA Cable > VGA/DVI adaptor > TV
vs
PC (VGA) > DVI/VGA adaptor > DVI Cable > TV

I.e. VGA Male TO DVI Female Adapter (HD15/M TO DVI-I/F)
instead of the standard DVI/VGA converter?