HiFive-U Early Board doesn't work

Hi, I just got my hifive-u early board from crowdsupply.

I start to follow “SiFive HiFive Unleashed Getting Started Guide” step by step in a ESD protected lab very carefully.

But it seems doesn’t work after the power on.

  • no console output from usb-uart (@115200)
  • no heartbeat light (wait at least 1 min)
  • no link light toggle for Gigabit Ethernet
  • I also try another MicroSD card and format the GPT and make DISK... format-boot-loader

JTAG response:

sudo ./bin/openocd -f ../openocd.cfg 
Open On-Chip Debugger 0.10.0+dev-g2c183e3-dirty (2018-01-03-10:25)
Licensed under GNU GPL v2
For bug reports, read
adapter speed: 10000 kHz
Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
Info : ftdi: if you experience problems at higher adapter clocks, try the command "ftdi_tdo_sample_edge falling"
Info : clock speed 10000 kHz
Error: JTAG scan chain interrogation failed: all zeroes
Error: Check JTAG interface, timings, target power, etc.
Error: Trying to use configured scan chain anyway...
Error: riscv.cpu: IR capture error; saw 0x00 not 0x01

First I check the SCK (pin16) of the ISSI nor flash, I found there is no toggle and clock.

Then I start to check on board power supplies.

I just found there is not power for both VDD_CORE and VDD_SOC_CORE.

Any suggestion? Thanks!


I found VDD_CORE and GND are short (very low resistance).

Do any LEDs turn on at all? What is the serial number printed on the sticker on the board?

It sounds like the board was “Dead on Arrival” - In cases like this, you should work with CrowdSupply to get a working replacement. CrowdSupply usually does not require a RMA number; they simply ask that you ship the board back. Be sure to follow their guidance on shipping (look under the “
Crowd Supply Store Product Return Policy (in-stock and pre-orders)” section of this web page: https://www.crowdsupply.com/returns). We will ensure that CrowdSupply has a board they can send you.

-M Hamrick, SiFive

Some LEDs flash when power on but totally random, some time there are no LEDs turn on.

SN: H5U-00062

Hi @mhamrick, thanks for your help.

Before I ship the board back to you/crowdsupply, do you mind I hack the board (include some welding work to find where short)? No sure I can fix but it do save time and money (shipping and tariffs).

BTW, did you test each board before shipping?


Please don’t.

We need to see which part failed and how our tests didn’t detect it before shipment.

Attempting to fix the board will make it difficult for us to figure out what part failed and why.


I replaced the U18 and the board start to work.