If you are having problems with your SR400 you can call us at
If you wish to try and fix the problem yourself, the user manual may be useful, and the following troubleshooting guide may be helpful too.
1) Instrument is unresponsive to front-panel button presses
Try a power-up reset. Turn the power off, then while holding the STOP key down, turn the power back on. After two seconds release the STOP key. If this doesn't correct the problem the instrument will need to come back to SRS for service. Click here to get an RMA number.
2) Having trouble using National Instruments Measurement and Automation with an SR400
Click here to download instructions on using National Instruments Measurement and Automation
If you are still having trouble your SR400, it will need to come back to SRS for service. Click here to get an RMA number.