Reddmango photo frame
Here's another one.... :). This one seems to give JTAG-like signal levels for a second or so after switch-on, then something happens and they all go to 3.3v, so it's possible you need to give the right JTAG command sequence in a short window. I've soldered a 6-way header to allow JTAG connection (that wasn't on the original frame).