flat cable pin order question

[john23]

Hello , I need to deside wich color was connected to which pin so I wont confuse pins on my amplyfier. shown in the attached photos.
there is a plastic bump on one side of the connector.
How can I know the  logic of this plastic 9 pin connector.
How can I see the logic of it?
How can I know which wire color connectin to what place in the plastic black connector?

[bostonman]

I'm uncertain if a standard exists, but I'd measure them. Looks like the ends of the wire are visible, so stick a probe in the wire, a piece of wire in one of the socket holes, and measure.

[pcprogrammer]

Usually there is also a pin 1 marker on the connector. This is an arrow symbol on the side of the connector where the bump is.

When you look at the connector with the plastic bump facing you and the pin openings down, the arrow should be on the left. The outermost wire is connected to pin 1, then next one to pin 2, etc.

Looking at your picture that would make the grey lead connected to pin 1, the white lead to pin 2, .. and the green lead to pin 8.

[john23]

Hello, I cant see any arrow as shown in the photo.
I see that grey is 1 and green is 8.
but I dont know the pin order in the black 4X2 box.
Is there some document or schematics regarding the pin order of such boxes?
Thanks.

[Someone]

Remember, this person has a multimeter:
https://www.eevblog.com/forum/projects/did-i-get-faulty-amplifier-question/

[pcprogrammer]

The arrow is a bit vague, but it is there. See that attached image.

Edit: Had to restart my computer to finish updates. 

For documentation on connectors like these, just look for information on manufacturers websites, like this one: https://www.jst.co.uk/productSeries.php?pid=168&cat=26

The pin order is from front to back and left to right. So 1 is front left, 2 is back left, 7 is front right, 8 is back right. Front is where the bump sits, pin holes facing down.

[jpanhalt]

It's not been explicitly stated, but wire numbers are likely according to the cable  (i.e., grey 1, white 2, black 3....) connections to a double row connector like that will have odd #'s in the top row (side with key) and even numbers in the bottom row.

From Wikipedia: Typically for headers attached to ribbon cables, the pins are numbered so they go linearly across the cable. Because of the way the connector attaches to the cable, this means in a two-row header, pins in one row have odd numbers and pins in the other row have even numbers.(emphasis added)

However, there are exceptions to that, so it's worth confirming with your meter.

[eutectique]

How can I know the  logic of this plastic 9 pin connector.

It's hard to tell without seeing what is attached to the other end of this cheerfully coloured cable. Do you have a picture? Then the logic would be apparent.