(408) 744-9040
(408) 744-9040
Home > Support > SR860 & SR865A Tech Support
SR86X Tech Support

If you are having problems with your SR860 or SR865A you can call us at (408)744-9040 and speak with an engineer, or email us using our technical support request form. If you wish to send the instrument back to SRS for service click here.

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.

Troubleshooting Guide

1) Instrument is unresponsive to front-panel button presses

Try a power-up reset. Turn the power off, then while holding the LOCAL key down, turn the power back on. After two seconds release the LOCAL 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

The input voltage preamplifier uses a low-noise matched JFET (LSK389B), Q202, as the front-end active component. This component is sensitive and may be damaged by overvoltage, including overvoltage from a static discharge (ESD). There may be situations in which the user suspects a damaged or destroyed input JFET. Symptoms of a damaged JFET can be excess noise, or partial or complete signal loss. The SR86x series lock-in amplifiers are designed to permit the user to replace the input JFET in the field if needed. The entire process should take about 90 minutes, including the 60 minute warm-up period needed after replacing the JFET before trimming the offset voltage.

For a detailed set of instructions on replacing the front-end JFET click here.

You can order the three replacement parts you need by clicking here.

3) Upgrade firmware in the field

Click here to download the firmware upgrade procedure.

4) Trouble communicating with SR865 LabVIEW driver

Click here to download instructions on using the SR865 driver with the SR865A and SR860 Lock-In Amplifiers.

5) Problem communicating over ethernet with a direct connection from my lock-in to the TCP/IP port on my  computer

Click here to download instructions on TCP/IP communication using a direct connection from your SR865A to your computer.

6) Problems with TCP/IP communications and Labview

Click here to download instructions on TCP/IP communications using Labview and the SR865A / SR860 Lock-In Amplifiers.

7) Need Python code for acquiring data from the SR86X

Click here to download the code.


If you are still having trouble your SR860 or SR865A, your instrument will need to come back to SRS for service. Click here to get an RMA number.

About SRS       Phone: (408) 744-9040