Display is dead, no function, but all voltages ok

Discuss Nava construction and related issues
  • ....i checked the two connections from the CPU to the crystal. Continuity is ok, but there is only a little DC voltage (checked with oszillograph)...maybe the CPU gets no clock? How should the signal on CPU pin 12&13 look like?
    That would make sense that nothing is working at all.....
    Thank you!
  • ...and i found out one more thing....the 5V i measured on the Pin 10 (Power supply) on the processor is measured against the "GND" Test point TP1. not against the GND Testpoint on the ICSP connector - its just round 2,5V.
    These two GND test points seem not being connected with each other...shouldn´t they be? Is there something like a "analog ground" and "digital ground"? Again thanks for any information!
  • HAHA!!! Solved the problem. On the PSU board i discovered there was a "R40" missing, which is not mentioned in the building instructions and not even found in the .brd file!!!!!!
    Nava 1.02 board: add a bridge where R40 is written on the PSU board - near J10.