What chokes are you referring to?
There's a choke just above the usb port, above the usb D+ D- test points and the esd device
What chokes are you referring to?
I can't measure continuity from the pads to the red side... I can sense on the green (on each pad / data line). Is that normal?
First try briccmii tool.
I have water damaged switch that behaves exactly same way... my guess problem around BQ chip... compare small elements around it....
You should have continuity from the green side to the red side, test on the red side for resistance to ground
I can measure 0.63MΩ and 0.64ΜΩ on top and bottom between the red side and the shield of the SoC
And have you got continuity between the green side and the red side
I have another switch that won't display anything when in the dock. It was another ebay no power purchase that I tossed a P13usb on. It looks like the repair was attempted but whoever did it lacked the skills to complete and managed to blow some caps off the VDD in on the side closest to the chokes.
I know these guys are for smoothing but can't I just short these pads?
BTW this picture is BEFORE I fixed it, lol. Please don't think I did this terrible job.
No, I don't have continuity between the two sides. I think this is the problem! I have continuity from the GREEN side to the pads (and the cable)
Yeah thats why you can't connect to pc you could remove the choke and bridge the 2 lines with wire to test before you buy some chokes.
Any idea how should I search for them? What package is this?
Thanks!
Are you talking about the caps on the 3v3 rail for vdd to the pI3usb or the caps on the data lines?
Pins 32, 29, and 26 looks like the VDD lines. If you look at my pic you can see they are missing. The specs sheet calls for caps but they are gone.
View attachment 180480
If you mean replace the caps with a wire, then you can't do that you'd be creating a direct short to ground.
Your original Photo isn't clear enough to really see anything.
I believe they are 100pf. I have an LCR meter en route so I will lift that last cap off the board, measure it, then try to replace that. Thanks for your help. I'll report back.
The caps are 0.1 μf, i'd also get yourself a new pi3usb and start again with that.
I did, I replaced it and I also had to run a line to one of the filters, it looks like the last tech lifted a pad underneath the chip you can see that on the bottom left pin where it was scratched off.
When I lifted the chip off that pad was gone.
In any event it works but it it doesn't connect to the dock at all and the USB C only works in one direction. I am thinking that new caps will solve that for that VDD, thanks for the update.