Velleman - P8115 - Display Contrast - Software Bug?

Who can help ?
After changing the CD4080B the unit worked fine.
In the menu, i turned down the contrast .
I cannot turn it up again ?

I only have a blank LCD.

Is ist possible, to do a reset ?

I hope you can help me !
If it is not possible, to make a hard Rest - this unit can not be used anymore !

Use Case:
Menü -> Contrast : there you have a number e.g. 37
Pushing the button right beside the LCD, it decreases the contrast.
I thought, it will decrease and than again raise again.
But no, it decreases until zero, then the LCD is blanck, and it is unpossible to use this
unit anymore !
It seems the microprocessor is storing this value. Even removing the battery, the LCD ist still blank !
It seems, there is a Software failure !
Decreasing the Contrast means, you must give this unit back for warranty to the reseller, it is not possible to use it anymore.

A reset isn’t possible.

But you can try this to get the contrast back on LCD.
Please try these steps:

  • Press the button for 2 seconds.
  • Press the button (short presses) 10 times.
  • Press the button for 2 seconds.
  • Then press the button multiple times (20 -30 times) until the contrast is correct.
  • Press the button for 2 seconds to exit.

Hope this will help.

If it doesn’t work with these step, you can bring it back to shop where purchased for RMA REQUEST.

Best regards,
Velleman Support.

1 Like

thank you very much, yes !!! :slight_smile:
it works now again !!!


Nice to hear it’s working again.
Have fun with this tester.

Best regards,