IMHO, if not for bug fixing, I doubt that Dell would spend time to tackle this "USB and power at the same time" improvement on the DV8P. What Dell will do instead is to release another model a few months later with such feature support. And maybe add on USB3.0 connector as well since the motherboard already supports it. The effort is minimum since they just need to fine tune the side case design in order to fit in the USB 3.0 port. Marketing strategy.
Reused a connector from a old laptop & soldered it onto the 2nd internal USB 2.0 port. Now I don't have to worry about ripping the little tabs off the board while testing stuff.
now I really want to add another USB port to mine but I'm not close to home or my soldering iron. And I would still need a space to put it. Maybe where the SIM slot should have been?
It always amazes me me what you Electronic Wizards can do. Congratulations for the initiative and success of the project! Two suggestions: 1) Offer people the service. I'm sure many here would like to get an extra 128Gb into their V8P. 2) Next, see if you can fix the Stylus!
Nice work with finding 5 volts! I'm a little wary about it though because I'm not confident it has any kind of overload protection. Its very likely that this is before the USB current measurement device and the power MOSFET that can disable this line. We also don't have a ton of headroom considering the USB is supposed to be limited to 100ma. It also seems to be powered up when the tablet is asleep but that's a minor concern in comparison to the overload protection. V3D, how did you find that second USB port? Do you know anything about CON7001 directly above it or was it just general probing that lead you to it? I've been pouring over data sheets looking for what that 60 pin connector directly above that second USB port could be. My hunch is its a high speed JTAG port or even better an LVDS connector for a second display. BTW all the pads are connected to something. Not one of them is floating. The internal display is a MIPI DSI display (a closed standard). This is unfortunate because if it was an embedded displayport we could daisy chain off the current displayport screen connector. If anyone has a broken DVP8 that they would like to donate, I'd gladly remove the atom SOC and probe out the pads. I would really like to figure out if we can get display out. There also seems to be a numbering theme on the board. The touch screen components all have the same beginning numbers and all of the sound components also follow the same theme. I thought it would be a good idea of posting some images of what is underneath the shields, so here they are:
I was also a bit worried because I didn't want to overload it, luckily so far I have not had any issues, even my headset with the volume all the way up worked fine & I was reading less than 0.01v change in voltage at the tab. If the voltage would of dropped under 5v I would have taken that as a sign that the USB device is pulling to much current for the circuit to handle. tablet on - active tablet off - not active. connected standby - active Found the 2nd USB port while probing around with my multimeter around the same time I found to 5v tab. There are tabs that are connected to the boards circuit traces but do not connect to anything else because of things that where never installed on this model. Just like how the USB data & the 3.3v tabs on the m.2 slot where disconnected the bigger tab next to the 5v tab is not connected to anything else on the board other than some dead end traces on the board.
Hey V3D, The driver for this 5 volt bus is a switching regulator. You will not see any drop until the regulator cannot keep up with demand. As you demand more current, the regulator will just boost more. If the regulator has over current protection then no big deal (a lot of them have built in now). I don't think its clear what I mean by "BTW all the pads are connected to something. Not one of them is floating.". I'm only speaking about CON7001. All of those pads on CON7001 are connected to something. They are either tri-stated, or actively driving some level. Tri-stating can be verified with a ohm meter set to mega ohms. If the pins are truly disconnected they will measure infinite ohms. If they are connected to something, you can read the leakage of the semiconductor that its connected to. Its usually 1-10 mega ohms.
any clue what CON5301 & CON5302 are? they sit close to the outside and obviously are meant for some sort of connection
I think they are pads for U.FL connectors and would be used for external Wi-Fi antennas. Hirose U.FL - Wikipedia, the free encyclopedia The traces also connect to these purple rectangles directly on the other side. These purple rectangles look a lot like Wi-Fi chip antennas.
