Pynq-z1 don't boot

After a few days (1-2 days to more than 1 month) without using pynq-z1, when I try to connect it, it does not boot. This has happened several times, most times I had to re-write the SD card. Can anyone tell me why this is happening? It’s a big problem to us, because many times we weren’t expect to spend time re-writing.
The red led turns on, and done led too. But Blue LD4 & LD5 and Yellow/Green LD0-LD3 don’t turn on.

Thank you

If the LEDs turn on, then the board is booting. If you are having problems connecting, it is likely the system clock is out of sync - this causes problems with some browsers - the cookie that is set for Jupyter can’t be set because the date/time of your PC is too far out of sync with the board.
This is a known issue.

I presume you are also only ever directly connecting to the board? i.e. it isn’t on a network? (If on a network with internet access the board will auto update date/time from internet timeservers. )
You can work around this by opening a terminal to the board and manually updating the system date/time.
The Chrome browser is more tolerant to date/time mismatches. Firefox and Safari are less tolerant.


Thank you for the fast replaying.
How do I update the system date/time? I’ve already opened the terminal. What I think stranger is that the Leds LD3, LD2, LD1 and LD0 didn’t turn on, and the setup guide says: " The Blue LD4-LD5 LEDs will then turn on and off while the Yellow/Green LD0-LD3 LEDs remain on. The system is now booted and ready for use."

I’m using ethernet cable, chrome browser, and when I use, it says: “no internet”

Thank you, again.

I have seen sometimes the boot process gets stuck in the u-boot. You can connect a terminal to your port and hit enter to see if you can see:


If so, type in boot and hit enter to let it continue to boot.

Thank you. I think my sd card has been corrupted, because when I tried the boot command this appeared:

Zynq> boot
Device: mmc@e0100000
Manufacturer ID: 6
OEM: 524b
Name: MSTran Speed: 50000000
Rd Block Len: 512
SD version 3.0
High Capacity: Yes
Capacity: 7.3 GiB
Bus Width: 4-bit
Erase Group Size: 512 Bytes
reading image.ub
4486524 bytes read in 830 ms (5.2 MiB/s)

Loading kernel from FIT Image at 10000000 …

Using ‘conf@1’ configuration
Verifying Hash Integrity … OK
Trying ‘kernel@0’ kernel subimage
Description: Linux Kernel
Type: Kernel Image
Compression: uncompressed
Data Start: 0x100000d4
Data Size: 4470640 Bytes = 4.3 MiB
Architecture: ARM
OS: Linux
Load Address: 0x00080000
Entry Point: 0x00080000
Hash algo: sha1
Hash value: 812783ce7146737951119919913d12c0640e4029
Verifying Hash Integrity … sha1 error!
Bad hash value for ‘hash@1’ hash node in ‘kernel@0’ image node
Bad Data Hash
ERROR: can’t get kernel image!

Did you know any reason to my sd card been corrupted while was inside pynq?

Thank you.

did you always sudo poweroff? It happened to me the power selection jumper was loose, the board shutdown abruptly and the SD card got corrupted