16 Posts

November 27th, 2007 18:00

Well another way to ask my question is - what are the pin functions of the (2x8) 16-pin box header plug which the signal cable connects to on the monitor's PCB?
 
Here is a photograph I have taken of the PCB inside the monitor which normally connects to the signal cable. I have detached the signal cable and only the box header plug - a kind of a biege colour I guess - appears.
 
  
 
Here's a thumbnail link to a high resolution image of that
 
 
 
Here is an enlarged view of the box header plug
 
 
Now I've just noticed in the photographs below, numbers on the socket, so I'll number the pins in the box header plug in the same way, thus -
 
 
 
 
And here is the (2x8) 16-hole cable connector socket at the end of the signal cable.
 
 
and viewed from the other side -
 
 
the pitch, or spacing between adjacent holes or pins in the same row seems to be 2mm.
 
So I am looking, if you like, for information specifying the pin assignment for the 16 pins of the box header - actually this is probably a better way to specify the information because as you can see, many of the signal wires are black, so a simple colour => function assignment may be confusing.
 
The subcontractor for the PCB seems to be Benq, so I guess they would know this information, even if Dell doesn't. I wonder if they have a forum to ask in?
 
So any ideas folks?


Message Edited by Peter Dow on 11-27-2007 02:07 PM

Message Edited by Peter Dow on 11-27-2007 02:30 PM

16 Posts

November 27th, 2007 18:00

OK so here is what I can guess from inspection of the photographs same as you.
 
Pin#       Wire Colour          Function?
    1         Blue->Black                  GND - B
    2         Brown                           ?
    3         Blue->White                 Video - Blue
    4         Yellow                            ?
    5         Grey->Black                  GND - G?
    6         White                             ?
    7         Grey->White                  Video - Green?
    8         Black(thick)                    ?
    9         Red ->Black                   GND - R
   10        Green->Translucent       Video - Green
   11        Red ->White                  Video - Red
   12        Green->Black                 GND - G
   13        Black(thick)                   ?
   14        Orange                          ?
   15        Black(thin)                     ?
   16        No wire
 
[Edit - Please note the post below "ALERT! It looks like the grey wire might be used to carry the green video signal"]
 
So not much to go on, but it is a start. Can anyone fill in the blanks?
 
For convenience, I'll quote the various pin assignments at the D-plug end of the signal cable,
 

 
 

15-pin D-sub connector


Pin Number
15-Pin Side of the Signal Cable

1 Video-Red

2 Video-Green

3 Video-Blue

4 GND

5 Self-test

6 GND-R

7 GND-G

8 GND-B

9 PC5V

10 GND-sync

11 GND

12 DDC data

13 H-sync

14 V-sync

15 DDC clock


So for example, I am guessing that Pin1 of the 16-pin header box plug on the monitor-PCB, if that pin truly is "GND-B" should be connected to Pin 8 on the 15-pin D-Sub connector on the graphics card side of the signal cable.

 



Message Edited by Peter Dow on 11-27-2007 03:12 PM

Message Edited by Peter Dow on 11-29-2007 01:32 PM

16 Posts

November 28th, 2007 17:00

OK so I removed the destroyed D-plug from the end of my signal cable and stripped back some of the insulation to get a good look at the cable.
 
 
 
There are various codes written on the outside of the cable in faint white print - such as "AWM STYLE 20276" which a quick google search tells me means " Appliance Wiring Material, Style number" but 20276 seems to be a general number which refers to a number of cables.
 
I've not been able to find a webpage which identifies that cable in particular or says anything like "and we recommend you use the orange wire for signal ..." unfortunately.
 
From inspection the cable has 5 thin wires, insulation colours - white, black, orange, yellow and brown. So that's 5 signals.
 
Plus 4 thick wires, consisting of outer coloured insulators - red, green, blue, grey covering a return ground shielding over a white insulator covering the central signal wire. So that's two signals per thick wire makes 8 signals for the 4 thick wires.
 
So that's 5+8 = 13 signals for the coloured wires. That leaves 2 signals unaccounted for, and they have got to be ground connections which are transmitted along the cable via the grounded shielding which is over all the signal wires and under the external black insulator of the cable.
 
Those two ground signals are at the D-sub plug end Pin# 4 and 11 and I deduced they correspond to the (2x8) 16 hole connector pin# 8 and 13 and indeed a simple continuity test with my multimeter confirmed those wires connect to the outermost metal shielding.
 
So that is another couple of signals to fill in the table as follows -
 
Pin#       Wire Colour          Function?
    1         Blue->Black                  GND - B
    2         Brown                           ?
    3         Blue->White                 Video - Blue
    4         Yellow                            ?
    5         Grey->Black                  GND - G?
    6         White                             ?
    7         Grey->White                  Video - Green?
    8         Black(thick)                     GND
    9         Red ->Black                   GND - R
   10        Green->Translucent       Video - Green
   11        Red ->White                  Video - Red
   12        Green->Black                 GND - G
   13        Black(thick)                    GND
   14        Orange                          ?
   15        Black(thin)                     ?
   16        No wire

[Edit - Please note the post below - "ALERT! It looks like the grey wire might be used to carry the green video signal"]

Message Edited by Peter Dow on 11-29-2007 01:33 PM

16 Posts

November 29th, 2007 17:00



Peter Dow wrote:
 
Some of the wires are obvious from the cable, - there are red, green and blue wires, which must be the red, green and blue video signals, and they seem to be wrapped with their respective return grounds.
 
But there is a grey (gray) wire and it has a return looks like. Which pin is that? There's an orange wire, and yellow, a brown. You see the problem?
 


ALERT! It looks like the grey wire might be used to carry the green video signal!
 
I've had a look at the layout of the PCB near the box header plug and done a wee bit of research on the GENESIS gm2110 "XGA/SGA LCD Monitor Controller with Integrated Analog Interface".
 
Note in particular how the green video signals look to come from pins 5 & 7 - which happen to be connected to the GREY ( "GRAY" ) wire on the signal cable!
 
 
I mean it is easy enough to check if you have a complete signal cable (which I don't). It is one of those things that if you don't suspect it, you won't look for it - it is easy just to assume that the green wire MUST carry the green video signal - but that is not the case. We need to check this and be absolutely sure.


Message Edited by Peter Dow on 11-29-2007 01:16 PM

Message Edited by Peter Dow on 11-29-2007 01:27 PM

Message Edited by Peter Dow on 12-01-2007 06:06 AM

16 Posts

November 29th, 2007 18:00

Here is an alternative procedure to map the 15-pin D-sub connector pin-to-wire connections, if you have a faulty cable and want to repair it.
 
I am assuming that you have no longer any desire to use your monitor in its faulty state - minus a colour, two or three - this procedure will render your monitor unusable until such time as you have completed your repair.
 
Obviously then the power cable has been unplugged for a while I hope.
 
The advantage of doing it this way is that you don't have to open up the Monitor - simply cut the signal cable clean through - not too near the D-sub connector, you want to leave yourself plenty of cable to strip the insulation back.
 
Make sure you take precautions against sending electrostatic sparks to the cable end which is still connected to the monitor.
 
 
Again, I'd love to be able to do this simple continuity test with my cable using my multimeter and post the pin mappings but as I have said - I stupidly blow-torched my D-plug and now I am living to regret that!
 
So I am looking for voluteers to either map the pin-to-wire assignments this way or by dismantling the monitor and determining the connections between the pins on the D-plug and the holes in the (2x8) 16 hole socket connector on the other end of the cable.
 
Come on volunteers - I can't complete my repair until someone helps me out by determining the pin mappings using one of the methods I have outlined!
 
Help me fix my monitor and I will help you fix yours! Can't say fairer than that! :smileyhappy:

16 Posts

December 1st, 2007 10:00



astronomer2002 wrote:
Unfortunately I cannot help as I essentially have the same problem. My cable was slashed when thieves stole my PC - but left the monitor. I have been trying for over a year to get exactly this info from someone. I got nowhere when asking Dell for assistance. I have even tried purchasing a dead monitor via ebay to get a cable or at least the pinout detail - but these monitors are rare and even dead ones go for silly money.
 
Hopefully someone out there who can help will read our plight.


Well you have helped make me more hopeful by merely replying to my post. :smileyhappy:
 
The thieves slashed the signal cable rather than just unplug it? Curious.  (Or maybe not - after all, they would have to unscrew the screws and if they were stiff, it might take too long, so just cut the cable, I guess?) They cut the signal cable clean through and took away your PC presumably with the D-sub plug and part of the cable still plugged into the computer? They went away, in other words, with one of these plugged into your computer?
 
 
Maybe it was that the thieves were really after :smileywink: - perhaps they needed the pin assignment information from that part of the cable in order to repair their own E151FPb? Perhaps taking the PC was just to disguise their real motives? :smileyvery-happy:


Message Edited by Peter Dow on 12-01-2007 06:45 AM

December 1st, 2007 10:00

Unfortunately I cannot help as I essentially have the same problem. My cable was slashed when thieves stole my PC - but left the monitor. I have been trying for over a year to get exactly this info from someone. I got nowhere when asking Dell for assistance. I have even tried purchasing a dead monitor via ebay to get a cable or at least the pinout detail - but these monitors are rare and even dead ones go for silly money.
 
Hopefully someone out there who can help will read our plight.

16 Posts

December 4th, 2007 17:00

Searching around the web turned up  "Identifying connections on unknown or cut monitor cables" 
and I'll quote what I think are the most helpful bits -
 

Identifying connections on unknown or cut monitor cables

Obviously, this is best done with a schematic.  However, since such a luxury
may not be possible, how can you go about figuring out where all the wires
go?  Easy answer - very carefully.

For the following, I assume a VGA/SVGA monitor.  You need to identify the
grounds, video signals, H and V sync, and monitor sense lines.  The procedure
is described with respec to a cut cable but if you are trying to identify
an unknown connector type on the monitor, the same comments apply to the
wiring **inside** the monitor.

First identify the grounds.  Use an ohmmeter between each wire and the shell
of the video connector on the monitor.  Resistance will be less than an ohm
for the ground wires.  These will often be colored black.  The shields of
the RGB coaxes will also be connected to ground.

The high bandwidth video signals will always use individual coaxial cables.
These may even be color coded red, green, and blue.  If not, you can determine
which is which later on.  If there are only three such coaxes, they are
the video signals.  If there are four, the extra one may be the H sync.
If there are five, the extra two may be the H and V syncs.  Testing
between these wires and ground with an ohmmeter should measure 75 ohms
for the video terminations.

Display a lively screen on your PC at a resolution you know the monitor
should support (remember, trying to drive a monitor of unknown scan rate
specifications beyond its ratings is like playing Russian Roulette.)
When in doubt, VGA (640x480, 31.4 KHz H, 60 Hz V) should be safe.

Turn up the brightness and contrast on the monitor.  If you are lucky,
even without any sync, there will be a visible raster.  Set it to be just
visible.  If there is none, then it should appear once there is valid sync.

You will need to bring out wires from the video connector on your PC.

Connect the ground of your video card to the ground wires you already
identified on the monitor cable.

Attach a wire in series with a 200-500 ohm resistor to H sync (pin 13)
on the VGA connector.

Momentarily touch the end of this wire to each of the remaining
unidentified wires (including the coaxes if you have 4 or 5 of these and
it is not obvious which are the video signals) on the monitor.  When you
find the H sync input, the raster should lock in and probably brighten up.
If the monitor was originally whining due to lack of sync, it should quiet
down.

Once you have located H sync, you can remove the resistor and connect the
wire up directly.

Now, attach the video signals.  It is likely that you will now have a
picture but it will be rolling on the screen.  Some monitors, however,
will not unblank until they receive both valid H and V sync.  Use your
resistor with the V sync output of the video card (Pin 14) on the remaining
unidentified wires.  Once you find the V sync input, the display should
lock in solid.


So if that is right, (and it looks to have been quoted on the web dozens of times) if the Dell E151FPb's grey coxial wire is indeed the green video, then maybe the green coaxial wire is the H-sync? And the green wire's shielding ground would be GND-sync maybe? It's all guess work so far ...

Pin#       Wire Colour          Function?
    1         Blue->Black                  GND - B
    2         Brown                           ?
    3         Blue->White                 Video - Blue
    4         Yellow                            ?
    5         Grey->Black                  GND - G?
    6         White                             ?
    7         Grey->White                  Video - Green?
    8         Black(thick)                    GND
    9         Red ->Black                   GND - R
   10        Green->Translucent       H-sync?
   11        Red ->White                  Video - Red
   12        Green->Black                GND-sync?
   13        Black(thick)                   GND
   14        Orange                          ?
   15        Black(thin)                     ?
   16        No wire

Now that article dates from 1996 so it is talking about CRT monitors rather than LCD monitors but maybe the procedure for finding V-sync might work? But I am asking myself if I am brave enough to try this procedure? :smileyindifferent: Probably eventually, if I cannot find the answers on the web I might have to.  Are you?



13.40) Replacing monitor cables or connectors

Many intermittent or erratic loss of color or loss of sync problems are due to a bad cable - more specifically, bad connections usually between the male pins and the wires. Or, perhaps, one or more pins were accidentally broken off as a result of the connector being forced in the wrong way around. Unfortunately, it is all too likely - particularly with newer monitors - that the shell is molded on and impossible to non-destructively remove to access the connector for wire repair or pin replacement.

  
  
  
  
  
Hence why I failed with both soldering iron and blowtorch to repair the D-sub plug. :smileyhappy:

Message Edited by Peter Dow on 12-04-2007 01:55 PM

16 Posts

December 6th, 2007 17:00

Using my multimeters I discovered enough about the wires and signals to attempt a first repair on the Dell E151FPb monitor signal cable.


Photograph: The final connections were soldered wire-to-wire. Initially, while testing, the connections were all made using 3-amp screw connectors of the type you see above being used to connect the external ground shielding of the whole cable. This enabled me to experiment and provided access for voltage and resistance readings using my multimeter.

Some signals and wires are not used for this first repair - the signal wires for the VESA Display Data Channel (ACCESS.BUS) signals remain unconnected. I still haven’t found out which wire (brown, yellow, white) is which signal (PC5V,  DDC Data, DDC Clock).

The first thing I noticed about the operation of my computer when the monitor is not providing DDC signals is that Windows offers inappropriate and indeed impossible resolutions as choices in the “Display Properties - Settings - Screen resolution” options as well as the correct 1024 x 768 resolution.

Secondly, the driver for my graphics card assumes that the LCD monitor is an old-style CRT monitor, because they NEVER provide any DDC data.

So these are wrong assumptions by the software but it still works, if you choose the right settings, but perhaps it is less foolproof like this.

However, I can be reasonably confident about many of the pin/wire-colour/signal assignments - because my repaired signal cable employing this knowledge allows my monitor now to work!

Please remember that the following table’s pin numbers are referring to the numbering of the connector at the end of the signal cable which attaches to the monitor’s PCB via a (2x8) 16 connector.

Pin# Wire Colour Function?
1 Blue -> Black              GND - B
2 Brown                          Not Connected
3 Blue->White                Video - Blue
4 Yellow                         Not Connected
5 Grey 0> Black              GND - G
6 White                           Not Connected
7 Grey->White                Video - Green
8 Black(thick)                 
GND
9 Red ->Black                 GND - R
10 Green->Translucent   H-sync

11 Red ->White              Video - Red
12 Green->Black            GND-sync
13 Black(thick)               
GND
14 Orange                       V-sync
15 Black(thin) -                Self-test
16 No wire

------------------------

Now if you are repairing a signal cable, now you don’t need to open the monitor up or think about the connector inside. What you need is the mapping between the pin numbers at the D-sub connector and the colours of the wires in the signal cable.

The mapping I have used for this repair in terms of D-sub connector pin numbers is as follows.

Pin Number                            Wire Colour

15-Pin Side of

the Signal Cable

1 Video-Red                            Red -> White
2 Video-Green                         Grey -> White
3 Video-Blue                            Blue -> White
4 GND                                     Green (Coaxial Ground shielding)
5 Self-test                                 Black (thin)
6 GND-R                                 Red (Coaxial Ground shielding)
7 GND-G                                 Grey (Coaxial Ground shielding)
8 GND-B                                 Blue (Coaxial Ground shielding)
9 PC5V                                    Not connected
10 GND-sync                           Green (Coaxial Ground shielding)
11 GND                                   Green (Coaxial Ground shielding)
12 DDC data                            Not connected
13 H-sync                                 Green -> Translucent
14 V-sync                                 Orange
15 DDC clock                           Not connected

Note that I have connected the signal wire “Green (Coaxial Ground shielding)” to three D-sub pins - 4, 10 & 11. That wasn’t my idea - the new cable I bought to use for the repair had all those 3 pins connected to the one wire.

The new cable I used.

For your information, though this is NOT a recommendation, the new cable I bought to cut in two and use is a “Manhattan MH SVGA Monitor Cable HD15M to HD15F, 6ft 1.8M. Made in China.” which cost me only £5 from my local computer parts store. Or at least that was what the bag it came in said it was.

The only advantage this cable had was that it was cheap. Its disadvantages are that it doesn’t have any of the DDC signal wires. In total it has only the 3 coaxial video wires and four thin wires making a total of 3x2 + 4 = 10 signal wires whereas I would have needed 13 signal wires to get the DDC signals working.

I should have expected something was missing before I bought the cable because on inspection of the D-sub plug of the cable, it has NO pin 9 at all!

My procedure to figure out which wires to solder to which

Whatever your new cable you buy and cut in two, then you need to identify which wires of your new cable correspond to which D-sub pin numbers (using a multimeter in Ohm or continuity mode) and then solder the same pin numbers together).

So for example, I needed to connect the E151FPb signal cable wire coloured “Green translucent” (being the H-sync wire) to pin 13 of the D-sub connector. But pin 13 of D-sub connector of my new cable was connected to the new cable’s white wire. So therefore I had to solder the white wire of the new cable to the green translucent wire of the E151FPb signal cable.

Further tips on mapping signals for other cables.

It might be worth adding a few words about this which may come in useful for other signal cables for other monitors.

Identifying connections on unknown or cut monitor cables 2: The LCD generation.

First of all, I connected up the wires I was reasonably confident of - the grounds and the video signal wires.

Using my multimeter in Ohm/resistance-measuring mode, I discovered that green-translucent wire suspected to carry the H-sync signal had the same resistance to ground of about 9.6 k Ohms as only one other wire and I guessed that both H-sync and V-sync might have the same resistance to ground. So that gave me a suspect for V-sync too.

When I came to do power-on tests on the reassembled monitor, I had to find the right wire for the self-test signal first of all because otherwise, the monitor would stay stuck in self-test mode.

Using a series resistor for safety as suggested, I tried the black-thin wire first because it seemed to be the only pin with a unique resistance (11.6 k Ohms) to ground. The other unidentified pins (presumably the DDC pins) had a very high resistance to ground.

I guessed right and the monitor stopped doing its self-test routine and just displayed a black screen. I found that was all I got until I had connected both the suspected H-sync and V-sync wires, at which point the monitor worked!

Not like in the old days of CRTs when the CRT would give you some encouraging feedback as you got more and more connections right. So although it was satisying to see my monitor suddenly working, :smileyvery-happy: there was no building excitement with tell-tale signs of it beginning to work, as for example was seen in the film "Crimson Tide" …

“Con. Radio. We are receiving flash traffic. Emergency Action Message. Recommend Alert 1.” - Vossler. (From “Crimson Tide”, the movie)

So I needed to do all that research before and resistance and voltage measurements while attempting the repair because there really were too many permutations of wires with signals to happen upon exactly the right connections by trying them at random to see what worked, or nearly worked. It was all or nothing really.

This first repair really did depend on well educated guesses and hunches, using further information available on the web and making and correctly interpretating the measurements I made with my multimeter.

Now since my monitor seems to be working well enough, I may not bother to do an even better repair, including the DDC signals, unless I come across a really good reason for doing so. But if you decide to go one better, please post here and tell the community of E151FPb owners how you got on and what are the colours of the various DDC signal wires.



Message Edited by Peter Dow on 12-06-2007 01:44 PM

December 7th, 2007 08:00

That's good news!
 
I too have got mine working - but by purchasing a second hand monitor and checking at the pin-outs
 
Whilst this is not guaranteed as I do not have the circuit diagram and the plug on the cable is molded these are the additional connections to the main ones you have already found.
 
 
Brown wire from the board goes to pin 9 on vga
Yellow wire from board goes to pin 12 on vga
White wire from board goes to pin 15 on vga
 
Pins 4, 10 and 11 are tied to common ground on vga
 
 

16 Posts

December 10th, 2007 19:00



astronomer2002 wrote:
I have even tried purchasing a dead monitor via ebay to get a cable or at least the pinout detail - but these monitors are rare and even dead ones go for silly money.
 
Hopefully someone out there who can help will read our plight.
 
....
 
That's good news!
 
I too have got mine working - but by purchasing a second hand monitor and checking at the pin-outs


 
 
So we helped ourselves. :smileyhappy: :smileyhappy:
 
Well I hope you didn't pay silly money for your 2nd hand monitor, another E151FPb I presume? I must say that some of the new 22" monitors on the market now, which go for about £160 or $300 look good value this Christmas.
 
So now you have two monitors. Unfortunately, the E151FPb only has a VGA connector, and no DVI port so it isn't easy to run both monitors from a standard computer graphics card, which seem to have one VGA, one DVI and one 7 pin DIN plug unless you get an adapter from say DVI to VGA.
 
Or maybe you will just sell one of your two E151FPb monitors?
 
Did you figure that Kensington Lock out, or just force the monitor open, as I did with by prising a screw-driver or some such along the seam?
Mine seemed to snap back into place on reassembly but I added some black insulating tape along the seam just to be sure.
 

astronomer2002 wrote:
Whilst this is not guaranteed as I do not have the circuit diagram and the plug on the cable is molded these are the additional connections to the main ones you have already found.
 
 
Brown wire from the board goes to pin 9 on vga
Yellow wire from board goes to pin 12 on vga
White wire from board goes to pin 15 on vga
 
Pins 4, 10 and 11 are tied to common ground on vga


So that means we are recommending this
 

Pin Number                            Wire Colour

15-Pin Side of

the Signal Cable

1 Video-Red                            Red -> White
2 Video-Green                         Grey -> White
3 Video-Blue                            Blue -> White
4 GND                                     Green (Coaxial Ground shielding)
5 Self-test                                 Black (thin)
6 GND-R                                 Red (Coaxial Ground shielding)
7 GND-G                                 Grey (Coaxial Ground shielding)
8 GND-B                                 Blue (Coaxial Ground shielding)
9 PC5V                                    Brown
10 GND-sync                           Green (Coaxial Ground shielding)
11 GND                                   Green (Coaxial Ground shielding)
12 DDC data                            Yellow
13 H-sync                                 Green -> Translucent
14 V-sync                                 Orange
15 DDC clock                           White

Good luck to everyone else with their repair!

December 10th, 2007 21:00

Buying a working monitor for £35 to get the pinout was taking a chance - but I figure I can sell it again with little loss. A dead monitor still goes for £20 or more. Last year a working monitor was at least £50 so I guess they're reaching the end of their useful life. Opening the case was interesting the first time - the second one was much faster and easier!
 
My biggest problem now is I cannot find the metal bracket that connects the base to the monitor! It's been in pieces for at least two years according to 'the boss'. My how time pases.

16 Posts

June 11th, 2010 04:00

My initial repair proved to be unsatisfactory in use over the years because the conducting wires alone are not strong enough to take the strain that the cable endures when plugging and unplugging for storing the monitor and setting it up each time.

The monitor cable also includes plastic rope strands in parallel with the conducting wires to take the strain and a satisfactory repair would need to provide an alternative method of protecting the connections from being ripped apart when the cable gets tugged as it will sooner or later no matter how careful you think you will be.

Much time has been wasted re-soldering the connections in the original repair and so finally I have come up with a design for a proper repair which includes the use of a piece of aluminium angle to take the strain and a plastic pipe to protect the wires from getting snagged.

The plastic pipe is bolted to the aluminium angle.

 The cables are tied to the aluminium angle by plastic-covered wire cable ties that I had accumulated over the years from various products. I knew they would come in handy one day! :emotion-2:

Plastic pipe removed so you can see the connections between the two cables.

Well I am feeling more confident about my new repair but only time will tell if it is good enough in practical use.

 

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