P
Q
Now connect the USB cable of the VARIOSAND hourglass to a USB port (e.g. power bank or mobile
phone power supply). Now all the LEDs should trickle down from the top like the sand in a real
hourglass. If this does not happen, the following list may help you to check possible causes:
VISUAL INSPECTION:
Now we can move
on with Q:
Not working,
nothing happens!
Individual LEDs
do not light up
No time change
when turning the
rotary wheel
There is no signal
after the time has
expired
Malfunction:
Troubleshooting:
USB cable correctly soldered with the correct polarity? Powerbank fully
charged? Check transistors for short circuit
Check all solder joints on the processor for short circuits
Re-solder the solder joints of the malfunctioning LED with some solder.
Check the solder joints of the resistors Is the LED soldered the right way
around? Is the "-" on the negative? If necessary, desolder and turn 180 degrees.
Check and re-solder all solder joints on the encoder
Check the piezo (buzzer) for polarity and re-solder the soldered joints.
Preset time cannot
be programmed
Check and re-solder the solder joints of all the buttons.
WELL DONE!!
Just sit back and relax and let
your mind wander a little.
When you are fully chilled out,
take another look at the the
assembly instructions from the
beginning and check whether
you have done everything as
described in the instructions.
Pay particular attention that no
short circuits have occurred
and that the values of the
resistors, etc.
are correct.
Everything OK?
