Internal USB Bluetooth mod

Flashback!

Last year I wrote an article about adding an internal USB Bluetooth module to my Averatec AV1050 sub-notebook and Hack-a-day picked up the story…

I added an internal USB Bluetooth module to my AV1050 without sacrificing the existing 2 USB ports! Other people have modified notebooks by adding internal USB Bluetooth modules, but have generally lost the functionality of a USB connector (see link).

Below is a description (including pictures) on how I did it and what I did. I’m keeping the instructions generic so that other people can try this on other notebooks similar to the AV1050…

Here I assume that you know how to take apart your AV1050 (see link), including how to remove the motherboard. I also assume that you know how to perform precision soldering with a fine-tipped low-power iron and that you have access to magnifiers.

DISCLAIMER: If you don’t feel confident with taking apart your notebook or with performing precision soldering, then I suggest you don’t try this mod. I’m not responsible if you damage anything.

On the AV1050 only 2 USB connectors are available to the user, but 3 USB ports are reported in the Device Manager. Like many other notebooks the AV1050 uses the Intel Centrino chipset with integrated 852/855 graphics. This chipset features an embedded USB controller with 3 ports (see PDF).

So where is that missing 3rd port? What can it be used for? One of the missing features of the AV1050 is built-in Bluetooth. I use Bluetooth a lot and I don’t like having an external USB dongle sticking out from one of the USB ports.

I looked at the Intel chipset data sheets (see PDF) and located the pins used for the 3 USB ports. After taking apart my AV1050 I disconnected the hard drive and removed the motherboard and looked with a magnifier for traces originating from the appropriate pins on the Intel chipset (which is located underneath the track pad). I noticed 3 pairs of traces running parallel to each other and originating near pin A20 (see picture).

One of the trace pairs ends after a couple inches, while the other 2 trace pairs continue along the motherboard towards the 2 USB connectors… Tada! I asserted that the trace pair that ends was the missing 3rd port. Luckily the trace pair ends on 2 test points. One is located underneath the track pad (labeled USB Data 1 in this picture & this picture) and the other is located on the other side of the motherboard underneath the hard drive (labeled USB Data 2 in this picture & this picture – note that that’s a green wire I soldered to USB Data 2, not a trace on the motherboard)

I used a multimeter to find +5V and ground points on the motherboard. Conveniently I located both very close to USB Data 1 test point (see this picture & this picture). Note that the translucent yellow areas are Kapton insulating tape used to hold everything in place.

The next step was to find a suitable USB dongle to take apart. I settled on the Zonet ZUB6111C (see link) for its small size. low cost, and widely supported Broadcom Bluetooth module (AFAIK, it is identical to the D-Link DBT-120). After taking it apart, I removed the USB connector from the Bluetooth module (see picture)

I then soldered wires from the USB Data 1, +5V and ground points as well as from the USB Data 2 point (on the other side of the motherboard underneath the hard drive) to the Bluetooth module. After reconnecting the hard drive, I connected the motherboard to an external monitor and to the AC adapter and pushed the power button… Success! Everything is working just fine :)

The tricky part was to package the Bluetooth Module inside my AV1050 without physically interfering with anything else. I wrapped the Bluetooth module in Kapton tape and wedged it on the motherboard underneath the track pad between the Intel chipset and the MiniPCI slot (see picture).

I reassembled my AV1050 and Bluetooth reception is good. Both USB connectors are also working fine. So there you have it :) I’d originally snapped more pictures but I accidentally deleted them. I used my Sony Ericsson W800i to take the pictures and then scaled them down to 640×480 and annotated them.