PTPM754DR Pinout like in the datasheet (https://www.mikrocontroller.net/attachment/52583/tpm754.pdf) of the old IC TPM754, you have to omit the pins 15, 16, 17 and 18 of the PTPM754DR (they are connected to GND), the other pins are the same as on both IC versions
Having a look at this on a proper monitor I can't see where the traces go as there's a sticker and cable in the way, as well as the traces hiding under the chip itself.
I found this thread (https://geekhack.org/index.php?topic=8971.0) discussing the same chip and a couple have 8 pins used in the connector, following links to deskthority revealed more but none quite the same as yours. To quote from here (https://deskthority.net/workshop-f7/t400-keyboard-trackpoint-pinout-t7678.html):Quote from: wysiPTPM754DR Pinout like in the datasheet (https://www.mikrocontroller.net/attachment/52583/tpm754.pdf) of the old IC TPM754, you have to omit the pins 15, 16, 17 and 18 of the PTPM754DR (they are connected to GND), the other pins are the same as on both IC versions
So if you have a multimeter you could test continuity from the pins on that chip using the schematic on page 3 to work out what goes where.
If that's like an alien language to you perhaps it would be easier if you said which keyboard or laptop you found this trackpad in, it might help with searching for someone who's already done the work.
Or you could take off the sticker and post another pic (and one with the ribbon bent up out of the way?) and I'll have another go at tracing it out digitally - if possible a clearer pic of the side with the chips would be great too, I'm not sure some if I'm seeing vias (holes which link to the other side) or not in a couple of places. Looks like you're in Australia so pics taken in direct sunlight should come out nicely :thumb:
It's on my todo list, 'just' need to mirror one side, transparent the non traces and make the traces a contrast colour then overlay both sides and it might make sense. If not delete more bits off the overlay until one trace is clear before repeating for the next. The strange distracting clicky noise is back in my computer else I'd be doing it now...
Edit:Progress pic attached, will look at pinout tomorrow. .xcf has purple as a layer if you want to have a go :thumb:
2 model M's I got for dirt cheap
2 model M's I got for dirt cheapWhere on earth did you get cheap model m's down here?
I've looked at this and my pic is much prettier now, but not got all the PS/2 pins connected to the ribbon header and just noticed it's 1:30 so I should sleep!Show Image(http://i.imgur.com/Yjn8IcC.png)
Red (5v) isn't a direct connection to the ribbon, could be a capacitor to smooth voltage or could just be the wrong pin (quite important if you don't want to fry it :)))
White is GND and I suspect yellow is too - can you confirm?
Pink is CLK
Orange is DATA
Do you want 'mouse' buttons too?
I've looked at this and my pic is much prettier now, but not got all the PS/2 pins connected to the ribbon header and just noticed it's 1:30 so I should sleep!Show Image(http://i.imgur.com/Yjn8IcC.png)
Red (5v) isn't a direct connection to the ribbon, could be a capacitor to smooth voltage or could just be the wrong pin (quite important if you don't want to fry it :)))
White is GND and I suspect yellow is too - can you confirm?
Pink is CLK
Orange is DATA
Do you want 'mouse' buttons too?
do you have which one description about this pin? like GROUND, RESET, VCC, BUTTON and other pin
do you have which one description about this pin? like GROUND, RESET, VCC, BUTTON and other pin
Sorry but no, I never had the trackpoint and my computer died so I left Wingklip hanging and he(?) didn't post any multimeter findings.
The datasheet linked above is still available, do you have a multimeter or continuity tester?