DSO150 signal line problem

[tomtom38]

Hello,
first the device works, but since few days the signal linie is at the top of the display.
I do not calibrate c3 or c5.
VPOS reset and trigger have no effect.

https://ibb.co/m25cKx

[RobNL]

Set your switch on DC, it's now on AC.

[jye1]

@ tomtom38:

Please adjust sensitivity lower (the number larger) and also move the left border triangle lower. 0.1V/DIV is too high for 3.3V signal.

[tomtom38]

All settings have no effect.
Normally with the V Pos setting the signal line have to be in the middle.
I think now that is a hardware damage
Once It got 11 Volt for few seconds .
What can die first with an overvoltage?!

[tomtom38]

The Problem is there is no negative Voltage.It seems U5 is damage

[AlexS16]

The Problem is there is no negative Voltage.It seems U5 is damage

Are you sure about that? my scope has the very same problem

[jye1]

U5 could be die if over voltage was applied. Please check V- and AV- with multimeter. If it is gone then that's the problem.

[tomtom38]

very sure UB is on Pin 8 /U5
but Output is a low positiv Voltage.
@jye1 from witch manufacturer is the ICL
I bought ICL7660SCBA Super Voltage Converter Intersil SO-8 1pcs
I hope that is similar.

[jye1]

ICL7660SCBA can replace ICL7660 and is better.