e-licktronic Forum

Hello, i just wanted to boot my first Nava, but i get no response on the display, no LEDs lit etc....
Voltages are fine. Pin 1 on IC118 (MCP4822) is 5V, Pin 2 of the LCD Display is also 5V, and on the ICSP connector is also 5V where it should be. Pin 10 of the Processor has also 5V like it should be. I can even see the red display backlight lighting up from the backside, but beside of that the unit does´t do or display anything and the display remains black.

I would be very thankful if someone could tell me where to start in order to get it working....

Thank you
Konrad

....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.