unresponsive board

[egentalen]

Hi,

I received my board yesterday, and after setting up the SD card per instructions and connecting a 2A power supply, all that happens is one green LED blinks about every 1.5 seconds. the reset button has no effect on this at all. I'm quite sure the SD card is set up right and the power supply is definitely right. Those were the only suggestions I could find on the forums. Anything else I should try, or is the board dead and in need of replacement?

Thanks
Egentalen

[9600]

You could try to see if there are any clues being output there. I'd also try a second SD card just to be sure you haven't got a defective one.

Have you affixed the heatsink to the Zynq chip? Could also be worth pointing a fan at the board, although I'm not sure it would overheat that fast if cooling were a problem.

If the power supply you are using is not the one supplied, I'd also check that the barrel connector is of both the correct inside and outside diameter, since if it is not the supply may be intermittent.

Regards,

Andrew

[shodruk]

Also, try booting without any USB peripherals and HDMI.

[aolofsson]

Please note that when you power USB periphetals , current draw gets up to 1.35A. We found that 3 of 4 different supplies rated at 2A bought on eBay and Amazon failed to create clean levels. As shodruk suggested, can you check without any cables connected to see if the light stays on.

This may not be the issue in your case but the symptom of a blinking led light would suggest that the power levels are not correct.

[egentalen]

I did try booting without the usb peripherals, and booting off a different SD card. It still looks the same - blinking every 1.5 seconds. It also looks that way whether or not the SD card is in, for what that's worth.

The power supply was labelled as "5.5mm/2.1mm". I just measured it and it is right. It is a pretty tight fit, so that would seem to be ok.

Not sure what else to try...

[gceline]

Everytime I have seen a blinking LED it has been the PSU that has been the problem. Please try another 5VDC minimum 2A PSU with 2.1mm x 5.5mm and the polarity should be center positive.

[aolofsson]

for reference, here is the experience of janos who got his board to work after some initial power issues.

viewtopic.php?f=9&t=987

It again shows that many 2A supplies may be ill suited for the Parallella.

Andreas

[Janos]

The use of a serial console cable was of massive help. Without it I would never have been up and running.

[leon_heller]

FWIW, I got my board yesterday, and have just tried it with a Stontronics 5V/2.5A PS, with nothing attached and no SD card (I'm just going out to buy one). The LED stays on all the time, no blinking.

[egentalen]

So, getting a new power supply (2.5A fwiw) changed things. The LED now comes on solid and stays on, and the board now warms up pretty fast (never got warm before). so far so good.

but, it doesn't boot, and the serial port is totally silent. I've set the parameters according to http://elinux.org/Parallella_UART_Connection

tried switching the Rx and Tx connections back and forth, but still silent. I can move the same wires over to a raspberry pi and watch it boot, so I think I have everything set up right.

Thanks for your help.
Erik