(408) 744-9040
(408) 744-9040
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SR510 & SR530 Tech Support
SR510 & SR530
Tech Support

If you are having problems with your SR510 or SR530 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 REL (SR510) or LOCAL (SR530) key down, turn the power back on. After two seconds release the REL (SR510) or LOCAL (SR530) 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) Front-panel red overload LED is constantly lit

Most likely the front-end transistor of your lock-in amplifier is damaged. If you look in the SIGNAL AMPLIFIER 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 is a 2N6485 FET (Q101). Your instrument will be populated with a 2N6485 or an LSK389B (newer units) depending on its age.

Take the top cover off your instrument and locate Q101. Look to see if you have a 2N6485 or an LSK389B in your instrument. If you have a 2N6485 you will need to order the LSK-ASSY assembly. If you have an LSK389B, you will need to order an LSK389B.

You can order the replacement part you need by clicking here.

3) Problems using National Instruments Measurement & Automation Explorer

Click here to download instructions on using National Instruments Measurement & Automation Explorer.

4) Can't send commands remotely over GPIB interface

A modification to the GPIB interface of the SR510 and SR530 was implemented in June 1991. A 270 pF capacitor was added between pin 10 (ground) and pin 17 (DAC) on the GPIB bus driver (part number 75161, adjacent to the MC68488 controller). If you have an old unit, check to see if there is a capacitor installed between pins 10 and 17 of the 75161 chip (located near the GPIB connector). If a 270 pF capacitor isn't soldered between these pins, you will need to install one before GPIB communication is possible.

5) I need a faster time constant than 1 ms

Click here to download instructions on modifying your instrument for a faster time constant.


If you are still having trouble your SR510 or SR530, your instrument will need to come back to SRS for service. Click here to get an RMA number.

About SRS       Phone: (408) 744-9040