We have a lakeshore temperature monitor ( model 211) connected to a cryo pump. Recently, The temperature monitor showed a communication fault with the temperature reading frozen on the display. After we removed the 5 V DC supply and put it back, the display went totally blank. We checked the input supply and it was fine. Any suggestions on what could be wrong in the monitor?
Post by Lake Shore Jeff M on Mar 13, 2019 7:09:20 GMT -5
Over the years, the Model 211 has undergone several design changes so what I suggest is that you remove the Model 211 from the enclosure. To do this remove the 4 screws from the corners of the rear panel and slide the monitor circuit board out. Look on the board near the 5V plug connector and see if you have a 5x20mm cartridge fuse installed on the board. If yes, remove the fuse from the holder and check the continuity of the fuse using an ohm meter. If it reads open, replace it with a 5x20mm 800mA, Time Delay fuse and see if the 211 starts working. If not, the 211 will need to be returned for a repair at he factory.
If you do not find a cartridge fuse, look over the circuit board to see if you have a different fuse which would be labeled F1 on the circuit board. If you find a different model, please send a picture if the component to [email protected] and we will provide additional information on how to test and resolve an open fuse condition.
Post by Lake Shore Jeff M on Mar 13, 2019 13:02:03 GMT -5
Other than verifying that the 5V supply is actually providing 5V to the circuit board, there is nothing else you can do.
To return the 211 for a repair, please contact our technical support department at [email protected] to arrange a Return Authorization (RMA). We will need your complete contact information as well as the serial number of the defective Model 211 in order to issue a RMA.