one thing that really annoys me for months is the “disapperance” of my raspberrys in case of a hard reset aka pulling the powerplug.
My last “experience”: the setup gui didn’t appear on one of my RPi 3B+ with Hifiberry Amp2. So, I pulled the power plug, waited 5 seconds and replug it. The result: nothing No sound, no connectivity via app, not visible on the wifi monitor of my fritzbox. Software is about 3 months old (around 2.57+).
This was the fourth time within the last couple of months! Not only with AMP2 (with its separate power supply of 19V), but also on normal ones with piggyback hifiberry DAC.
Hi Thorsten,
in both cases, where does the PI take power from? The AMP and the DAC or it’s self powered?
This is because, just yesterday we discovered something interesting.
Context: first corruption cause of SD card is when they are provided with less than 5V.
We noticed on a product that having a capacitor on the power line, when power is suddenly removed, it discharges quite slowly, keeping the PI powered with a voltage that decreases constantly until gets to 0 (and not getting to zero immediately). We believe that this design pattern will result in SD Card corruption a lot.
Interesting observation, and also quite logical. Almost all wall wart (switching) power supplies use caps to smooth the output voltage. The more oversized the power supply, the longer it will need to drain - and generally we like our 3A power supplies on the Pi that draws ~250 mA. It will need a few seconds to drain. (To illustrate: I have a small circuitry that draws ~30 mA, powered by a 3A wall wart. It remains functional for more than a minute after unplugging.)
For this reason, when necessary I unplug the cable on the Pi’s side to kill the power instantly. So far I have had very little issues with that.
this is an interesting idea… I use an old Dell 19V-Power supply. The ones with Amp2 on top are powered by the Amp2. I will try to “fast shutdown” the power the next time the system itself is stugged. (hopefully this will not happen so early… ). Will keep you informed.
so, it happend again… Therefore, I cut the 5V power pins on the RPi that get the power from the AMP2 and use a seperate 5V-power supply. Will be interesting.
I also changed the SD card, because a friend of mine who has been working with RPis for years says, that sometimes the SD cards die during powere failure. I now switched to industrial types, they are not really more expensive than normal ones (10€ for 8GB).
This is quite interesting - apologies for hijacking Thorsten’s thread!
I’m running Volumio on a Pi3B and having problems with corrupted images.
I have been switching my Pi off on the mains socket - and noticed that as implied in this thread it takes a few seconds for the leds on it to die - I guess as the supply from the “wall wart” decreases - so perhaps this is why I’m getting the problem too!