Chromatography Forum

Hello,

Our HPLC machine pump, model JASCO PU-2080, is displaying an error message reading "TROUBLE UNDER PRESS !!". The pump was left running at 1mL/min recycling mobile phase for 4 days until this message was noticed and it had been working normally in the days and weeks before this.

If anyone has a manual with a trouble shooting guide for this specific pump (ideally with the location of the specific components of the pump) or could give advice about how to fix the issue, it would be much appreciated. Many thanks.

Generaly , under pressure means no solvent flow for a certain time.
Please check if the solvent reservoir is full and there is a pressure on the pump display during pump operation.

You may also check the lower pressure limit of the pump , if it is not set to a correct value.

I agree with Uzman here. However, the error message should be stored with a date and time so that you can narrow down how long the instrument has been running without solvent. It sounds like even though you were running solvent recycling, their may not have been enough and your pumps may have been running partially dry. I've heard mixed things about if pumps are able to run dry or not, but your pump may be damaged and the seals may be worn so I would be cautious trying to run anything else or you may end up getting a blocked line or something worse.