ChipSHOUTER triggers in terminal but HV capacitor does not discharge (no fault induced)

[thisisish]

I’m experiencing an issue with my ChipSHOUTER during manual fault injection testing.

Observed behavior:
• The device charges the HV capacitor normally.
• The terminal indicates that the trigger event has occurred (trigger message is shown).
• However, when the pulse is triggered:
• The HV capacitor voltage does not drop.
• There is no observable discharge event.
• No fault is induced on the target.
• No noticeable EM pulse is observed.

Expected behavior:
• Upon triggering, the HV capacitor voltage should drop as it discharges through the injection coil.
• A pulse should be emitted and a fault should be induced on the target device.

Additional notes:
• The capacitor charges to the configured voltage without issue.
• The issue persists after power cycling the device.
• The output coil and cables appear properly connected.

Has anyone encountered a similar issue where the trigger is registered in software but no discharge occurs? Any guidance on additional diagnostics would be appreciated.

[alex-dewar]

Hi,

Just to confirm, are you measuring the voltage of the capacitor using the oscilloscope outputs on your ChipShouter?

[thisisish]

Yes — while validating via the API commands, we are simultaneously inducing faults on the demo boards to observe any glitch behavior.

[alex-dewar]

Sorry about the late reply, got caught up with some other stuff. To be clear, I'm asking if you're using the Volt 20:1 probe output on the ChipShouter. API commands and/or observing effects on the target aren't a reliable way to confirm discharge of the capacitor.