Recently I ordered the above from Amazon Canada. I was looking forward to using them but the 30001 when hooked up to power didn’t power up at all and I switched to Adjustable buck converter and it was the same. Both show a short at the inputs when tested with my multi-meter. I was thinking of just re-ordering but my experience so far doesn’t give me a lot of confidence in your brand. I was wondering what you could do to sort this out. Just for simplicity I did not hook them up incorrectly and provided both with a initial 5v DC and later 12v DC from my power supply. I tested that before hand on my Multi-meter and verified it was accurate. So I am at a loss as to their failure.