ATNWG100 no red sys led; board dead?

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Hi,

I'm using an ATNWG100 and I have build a small addon board to interface with a camera module (omnivision OV3620). The interface board only consists of some wires. On this board no J5 / J6 pins have been shorted together. After I inserted the board (the camera module is not connected to it yet) the Linux kernel doesn't seem to boot anymore. The green power led is on all the time but the red system led is not coming up. Further I also am not able to connect to the board using a serial connection though I must say that I'm not sure whether I selected the right serial device (ttyS0, ttyS1 ..).

I have meassured the voltage on the VCC pins and it is 3.3V and further the cpu also isn't hot or so.

Does anyone have an idea what could be wrong and how to check if it is functioning? I susepct that perhaps the flash has been corrupted or so.

Thanks,

Roderick

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I just verified that the serial port of my PC is working correctly but I can't connect to the board. I don't seem to get any response from the board, so I also don't see u-boot.

The only things I see are the power led and the leds inside the LAN-port which are on.

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Can you check that the reset line isn't being held oddly? Your 1.8V rail is still on track etc? If you aren't even getting a uboot prompt then it's something fairly fundamental like this :-)

-S.

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I read the schematics and using them I measured some pins. There are a lot of test pads which are useful for doing measurements. Some are easy to find but a bunch of others (there are 15 near the cpu) are impossible to figure out. Is there some reference for them?

At least 1.8V seems to be up. I measured close to the tiny24 to confirm that but as I don't know well where to expect 1.8V it is hard. Further the reset is correct as it is correctly at 3.3V and drops to 0V if I press the switch.

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For reference I have attached the pinout of the addon board I build. It is connecting a Comedia AA3620 (small board around a Omnivision OV3620) to the image sensor interface of the NGW100. The digital and analog grounds are separate and are connected together on the NGW100 itself because J6-2 and J6-4 are connected.

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After a second opinion of a colleague it appeared that some IC was stuck in reset after all. A diode was damaged. It boots again :)