Non-deterministic startup/bootup

mafish

The Up2 6000 (x6425RE) I am using in my project has trouble to turn on properly.
The Up2 is turned by external microcontroller, by RECOM 12V 5A isolated power supply.

By default the startup sequence is that the MCU turns the 12V bus on, and waits for 50s for Up2 to boot up and communicate with it (systemd-analyze shows startup time of 34s to userspace and this is true when measured while rebooting).

This sometimes works but Up2 does not always startup properly. Sometimes it takes >90s to boot up, and sometimes it does not turn on all (blue LED next to power socket stays off). I can see that te voltage is supplied ( I do have indicator LED, and voltage measurement on Up2's 5V bus), but the board itself remains dark. The monitor connected to the board, turns on for a second and then goes to standby (indicating that 'something' triggering HDMI is happending).

I haven't noticed this when powering the Up2 for a regular ACDC power supply. Below there is a oscillogram of 12V bus when powering on:
As you can see the voltage rise time is ~10ms to 12V, which is rather long.

If anyone has any clue why the board does not turn on i would be thankfull for sharing.

mafish

Hi Wilbert, thanks for the reply.

I've changed now changed Power Supply mode to AT (from ATX) in the Up2 BIOS.
It seems my problem is no more.

Wilbert

Hi Sir,

Please make sure your power supply is in good condition.
If you think there is any problem with the motherboard, it is recommended to request a repair service to confirm whether there is a problem with the MB.
I have tested here, even if the power supply is ramped up very slowly (0->12V took about 1 seconds), the motherboard can still boot normally. Please check if your external device is affecting the UP2 6000.

Best Regards,
Wilbert Lee.

Wilbert

Hi Sir,

Glad to be able to solve your problem, thank you for your question.
Next time I will suggest related options for users to clarify similar issues.

Best Regards,
Wilbert Lee.