Started by aks, 12. Jun 2011, 16:18
there is always the option to connect the jtag from the cpu-top .. like shown here: http://www.t-hack.com/wiki/index.php/EJTAG_on_SMPit is definately not an easy task, but several forum users, were able to do it.
if there is mediaroom running on the box (which is very likely) then you cannot get anywhere with the serial connection.the only option is to patch the bootloader with JTAG during startup.
Hi aks, I realise that this is an old post but I have done the same thing and come to the same conclusion that JTAG-Enable TCK and TMS all run to ground.Taking this a step further and in the hope of being able repair this by cutting a few traces I decided to remove the chip from a second board and proceeded map each JTAG wire from the top of the chip to the balls underneath (unfortunately I could not find a datasheet for this chip and spent hours with a sewing needle taped to my multi-meter probe)The result were as follows JTAG-Enable TCK and TMS are attached to each other beneath the chip and then to groundTDO is not attached to anythingTRST_N can be found on the bottom of the board beneath the chip TDI can be found on the top of the board to the right of the chipI think it is therefore safe to say that this box cannot be modified. (please prove me wrong) The attached picture shows the pin outs on the SMP8634LF chip and also traces connecting JTAG-Enable TCK and TMS