if you look at my previous post (#9), the wire with the ferrite bead around it is the vga wire connecting to the monitor board.

Heres the link
http://forum.allaboutcircuits.com/attachment.php?attachmentid=19811&d=1274627428

 

where is the rest of that cable then?

 

its been chucked away ages a go - thats why this is such a problem lol

 

ahh.. so then I will need a close up of that VGA connector area on the board so I can figure out the tracks.

 

thanks for the help man. heres some pics. i used rapidshare so i can post extra large res. tell me if u need anything more. ive annotated 1 pic to show what i already know

http://rapidshare.com/files/390820079/pics.rar.html

 

Take a look at the pick
First check the RGB wire for an additional ground shield inside.
Second use the meter continuity check range to find out where the rest of the wire leads to on to the VGA board.
Identify them and mark them properly and post it.

{ed}
Oh by the way. You have to plug in the VGA connector to the board

 

http://rapidshare.com/files/390834673/pics2.rar.html

hope these clear up the problem

 

colour coded

 

OK Now comes a tricky part. With the VGA cable removed, put the monitor back as it was, I need some voltage measurements.
I have to know the DC voltage available at the color coding when the monitor is showing a test screen
{ed}
Or better yet you can measure them at the end of the cable, this way is easier
The monitor should be on, not in stand by. If it goes to stand by. Connect meter, power on and measure. really soon

 

i get ya. ill report back as soon as i have answers

 

Im off to take an electronic and electrical engineering test now for my degree, heres some progress I made last night. The following is info about the pins in the picture:

#1 to MYSON MTV312MV64 Chip
HSCL/P3.0/Rxd || I/O || Slave IIC clock / General purpose I/O / Rxd (open drain)

#2 to MYSON MTV312MV64 Chip
HSDA/P3.1/Txd || I/O || Slave IIC data / General purpose I/O / Txd (open drain)

#3 to MYSON MTV312MV64 Chip
DA5/P5.5 || I/O || PWM DAC output / General purpose I/O (CMOS)

#4
Pin > 100R resistor > Q buffer D > transistor

#5
Pin > 100R resistor > D inverter Q' >


This is as far as I have got, i'll be able to do more, and get some voltage measurements for you after this exam.

 

It looks like:
1 is SCL, VGA pin 15.
2 isSDA, VGA pin 12.

4 & 5 are almost certainly the two Sync signals, VGA pins 13 & 14 - but which way round is probably trial and error.

I've no idea on your #3. Anyone else?

I'm working on the VGA pin numbers from here:
http://pinouts.ru/Video/VGA15_pinout.shtml

 

Pin 3 could be a monitor info pin. It's an IO, so could be anything
The trick is to connect the RGB correctly ( if not only color error will show but there will be a picture)with the respective ground.
Connect all the ground.
Apply a 800 by 600 VGA resolution from the VGA card and connect HV sync one by one. Swapping will definitely identify the sync signals. U have to look in to the VGA diagram at rj post.
The monitor may go in to stand by without HV sync, you need to power of the monitor fro HV sync swapping.
Once established this connections. Connect the SDA and SCL properly.
Monitor ID have to be trial and error and to make these connections certain you need to restart windows after each connection as the VGA driver loading will identify the monitor model for proper sync and resolution refresh rates settings, and also to display the monitor model in the info tabs.

Remember first you need to establish RGB and sync, proper colour and to make sure apply the monitors native resolution to see if it works, if not then you need the other connections too, if it did then you are in luck. Make these connections permanent before any other connection.
And always reduce the resolution to standard VGA resolution to avoid confusion to the graphics card if it supports monitor ID signals.

 

Made progress guys!

Attached pic for info. Managed to trace back 2 inputs to vsync and hsync. now with sda and scl i only have 2 wires left - ID0 and ID2. I should just try them one way and then try them the other?

This has been a great success guys, very much appreciated the effort you have put in. Big thanks to R!F@@.

Last question, I have no Sync Ground (pin10) - is this normal?

Heres the content of text file i made whilst tracing the wires back

THIN GREEN
to MYSON MTV312MV64 Chip
HSCL/P3.0/Rxd || I/O || Slave IIC clock / General purpose I/O / Rxd (open drain)

THIN BLUE
to MYSON MTV312MV64 Chip
HSDA/P3.1/Txd || I/O || Slave IIC data / General purpose I/O / Txd (open drain)

THIN PURPLE
to MYSON MTV312MV64 Chip
DA5/P5.5 || I/O || PWM DAC output / General purpose I/O (CMOS)

THIN BLACK (THROUGH A RESISTOR AND A TRANSISTOR)
to MYSON MTV312MV64 Chip
DA2/P5.2 || I/O || PWM DAC output / General purpose I/O (CMOS)

THIN RED
to MYSON MTV312MV64 Chip
VSYNC

THIN ORANGE
to MYSON MTV312MV64 Chip
HSYNC

Heres the updated image

Hopefully people in my position will be able to read this thread and sort themselves out =]

 

Sync does not use an independent ground, it uses the normal ground as other data lines.
The RGB has an internal ground to isolate it from the next video line.
Have you been able to see a picture yet

 

Ahh good stuff, thats all the cables ID'd now =]

I am waiting on an order of a spare vga cable I am going to splice that I got off ebay. I will post back progress as soon as its made!

 

good..........

 

Oh before I get that VGA cable - the two sync pins from the myson chip went through two schmitt not gates each, before reaching the vga pins - what is the point of inverting a digital signal, then inverting it right back again?

 

doesn't matter, probably to buffer them.

 

Well after all that, heres the result I was after