If you are having problems with your SR810 or SR830 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 SETUP key down, turn the power back on. After two seconds release the SETUP 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) Red overload LED is constantly lit
Most likely the front-end transistors and op-amp of your lock-in amplifier are damaged. If you look in the CURRENT & PREAMPLIFIER page of the schematics (located in the back of the user manual) you will see that the first active components in the voltage input signal path (U102 and U108) are NPD5564 FETs from National Semiconductor. This part became obsolete several years ago. Since then, we have used several replacement parts in
Start by unplugging your instrument from the AC line. Then remove the top and bottom covers. Looking down from the top of your
Locate U102 and U108. These are the components that need replacing. They may be in an
You should also replace the current
You can order the three replacement parts you need by clicking here.
3) Offset and CMMR are out of tolerance
Click here to download the input offset and CMMR adjustment procedures.
4) Notch filter needs adjustment
Click here to download the Notch filter adjustment procedure.
If you are still having trouble your SR810 or SR830, your instrument will need to come back to SRS for service. Click here to get an RMA number.