Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

When A Waveform Fails to Appear



1) Make sure "TRIGGER" mode is in "AUTO" in case the Digital Storage Oscilloscope (DSO)'s trigger is not set properly with respect to your signal.

2) Make sure the DSO isn't in "HOLD" mode. You can check this by looking in the upper left corner of the display and making sure "RUN" is displayed. If "HOLD" is showing, then press the "RUN/HOLD" button at the bottom of the control panel once.

3) There may not be a signal there. Use the DMM feature of the DSO to check it out. See if a frequency is present. See if voltage is present. This may surprise you. If you know something is there but neither the DMM or the DSO can see it, recheck your leads and connections.

4) Make sure "GND" input coupling isn't selected. That pretty much kills all action.

5) Make sure the trigger source is on the channel you are working with (upper right part of the screen when you press the "CURSORS/TRIGGER" button).