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TMDS line tracing

A project log for G4 iMac Display Connector

One of the biggest pain points for repurposing old G4 iMacs is having to rewire the display connector. I’m designing a PCB to streamline it.

NavarreNavarre 05/19/2022 at 02:400 Comments

Today I finally got to tracing the lines from the TMDS connector on the LCD to the board connector. I need to double check everything before I commit to the board layout, but my preliminary findings are below.

As a reminder, this is an 800 MHz, 17" G4 iMac. The descriptions and cable colors are from DremelJunkie's website (http://www.dremeljunkie.com/2011/08/guide-step-by-step-17-imac-g4-tmds-to.html?m=1).

iMac board connector pin
(LCD) connector pin
LCD Cable Color
Description
122BlueVCC: 3.3V
223OrangeVCC: 3.3V
321GreenGROUND
420PurpleGROUND
53Red to Red
Rx2+
64Red to GreenRx2-
7GROUNDGROUND
86Orange to Red
Rx1+
97Orange to Green
Rx1-
10GROUNDGROUND
119Blue to Red
Rx0+
1210Blue to Green
Rx0-
13GROUNDGROUND
1412Green to Red
RxC+
1513Green to Green
RxC-
16GROUNDGROUND
1715RedVEDID: DC 3.3V
1819GreyGROUND
1917WhiteClock-EDID
2018BlackData-EDID
2124YellowVCC: 3.3V

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