I received my PicoCalc yesterday (21 July 2025). The Assembly was pretty much flawless. The instructions are quite clear and the only thing I did different was apply some double-sided tape to the back of the screen It’s not very strong but it does keep the screen in place during assy.
Anyway, I have two 18650, 3400 mAh Lithium Ion 3.7V batteries from UltraLast (Purchased at local hardware store.) I placed them into the back and pushed the Power Button for the directed 1 second. Nothing. waited and waited for several minutes, nothing. OK, so assume batteries need to charge. Plugged in a Raspberry Pi Power supply with USB C connection - Yellow LED by the PicoCalc lable comes on.
Tried the 1 second Power on again - Nothing. Assume that dead batteries will not allow power on so I take them out. With Charger only plugged in, press Power On for 1 second - Nothing. Press and hold for about three seconds - Boot Screen ! Joy. Checked battery voltages and they are 4.1V each.
Press Power button for 1 second to Power Off the Pico Calc - stays on. Wait for several minutes - still on. Pulled the plug - Power Off.
Installed batteries. Pressed Power button for about three seconds - nothing, Accidently rapid press Power Button and hold for thirty seconds and PicoCalc boots. Spent ten minutes with various power presses trying to turn off the PicoCalc. It’s bed-time so I remove the batteries.
Did some research today and decided to update the Firmware, assuming that there is a power button fix in the update. Using a new Pico 2 I flashed the Firmware (V6.00.03 for Pico 2) to the Pico. Gingerly removed the installed Pico H and installed the Pico 2.
Press Power Button for about 1 second - nothing. Press Power Button for about 5 seconds - PicoCalc boots. Pressed the Power Button for about 1 secon to turn it off - still on after about two minutes. Press the power button for about five seconds - still on after about five minutes. Press the Power button for about thirty seconds - sometime in the 25 minutes it has taken me to write this up, the PicoCalc turned off. I’m reluctant to try to turn it back on.
Any and All suggestions or directions are appreciated.
Some PicoCalcs had bad solder joints (think one was on the stm32), if you get nowhere email alex@clockworkpi.com with evidence of issues and he’ll post you out a replacement board in around two weeks.
Carefully remove and re-seat the core, ensure you don’t press down on the main board as LCD is underneath !. Try another core (with PicoMite installed) if you have one. Make sure batteries are charged and the right way round. Note keyboard shortcuts for display backlight (can’t be seen if too low).
Last thing to try, flash the stm32 keyboard controller with the v1.2 firmware (via dip switch on the main board and the main boards USB-C socket (NOT the one on the core)… Think I had a post with links in the early days.
Here we are…
Thank you for the response. I have tried two different Picos/cores. Same results. When it is on, everything works like it should. Backlight and screen will brighten up and dim down. Batteries are in properly. I’m pretty careful about polarities of batteries. One reason I put a Pico 2 in was to eliminate the core as the issue. I have a plethora of Pico products from Adafruit, Pimoroni, and Raspberry Pi but I figured to stay close to the original install. I will pull the motherboard and put it under a microscope tomorrow. Getting past my bedtime 
I recently got a picocalc and noticed the same thing with turning on and off: you have to hold for at least 3 seconds for anything to happen. I have updated the BIOS to v1.2 as described above and basic to 6.03.
Did it fix the Power On/Off issue?
Sorry. I guess I was not very clear. It did not change anything with the power button. The reason I updated the BIOS was due to the problem with mm.info(battery) not working.
Gotcha. Thank you for clarifying.
Two seconds for my power button…
Hello fellow PicoCalcers,
An update.
Under the microscope everything looked very good.
In the end I have found that the Power Switch is faulty. If I move the button around in the housing just right, the PicoCalc will boot up and shutdown.
I wrote Alex and described my issue and the steps I have taken. It’s Friday late here in the USA so I don’t expect to hear back from Alex before Monday but I thought I provide an update.
Alex has responded. A new board is on the way.
An update is warranted.
My replacement board arrived yesterday and I installed it this morning.
WOW! What a difference. Powers on and off with just a gentle press for about 2-3 seconds.
The response when working with Alex/Tech Support is awesome and almost painless. I say almost because nobody wants to have to deal with a bad product out of the box.
Anyway, now I can get on to learning the ropes with this awesome piece of equipment.