Hi,
Like fungus said, a screenshot would be helpful - But also a snip of the schematic.
Other questions:
- You measure the output of the driver, going to the gates of the switching FETs, right ?
- Are the outputs isolated by e.g. a drivertransformer ?
- Level of the switching signal, ON = xxVpeak ?
You see, a part of the schematic and screenshot will be...
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/wink.gif)
Also important: Short ways:
When measuring the NON-Earthed scope is connected to the circuit by connecting the GND clips or (springs) to Battery Negative (Circuit GND).
When you measure against GND as the common potential, there is a difference if you choose the nearest GND point or take someone somewhere which can be reached easily.
Plus the lenght of the GND leads from the probe..
Isolated Scope from TEK
A used one is not expensive, the last THS 710/720 were sold between 280...400€(ebay germany).