(non-X10) Trouble shoot a RF device

[petera]

You might want to check the white plug and it's corresponding connector on that board for clean connection. Also another area to check is the antenna connection to ensure the solder is good.

[bkenobi]

I removed the board from the housing (had to desolder the antenna from the metal stud).  Once clear, I removed the tape whatnot as well as the metal shroud that covers the GPS components (I assume).  I cleaned both sides with white vinegar and a tooth brush and then with water.  There was minimal reaction to the vinegar which could have been from manufacturing.

I located the 5v/ground connectors that are fed from the charge ports and fed them 5v and ground from my bench PSU.  I was expecting the charge LED to turn on, but nothing happened.

The main chip appears to be an ATMEL MEGA32L but of course I have no way to debug it.  Interesting that this thing is not much more advanced than an Arduino with a couple radios and custom code.

[dave w]

See if you can follow the traces from the charging port or the battery pack to a regulator chip and check for output there

[bkenobi]

I'll see if I can locate one.  the white connector pin 1 is ground and pin 2 is +5v (left to right).

[bkenobi]

When looking at the pictures, I did notice one area of the PCB that looks scorched next to a 6 legged DIP.  I don't know what it does or if that's normal for this board though.  I don't see anything on the opposite side, so I assume it's related to heat on that chip.

[bkenobi]

When inspecting closely through a zoomed picture on my phone, I can see damage to the SMD.  Any idea what the 6 leg "731" IC might be?