Intermittent late eluting peaks (but not all peaks) observed on 2695 - WKB260732

SYMPTOMS

• Late eluting peaks (but not all peaks) observed on 2695

ENVIRONMENT

• 2695
• Empower 3

CAUSE

Firmware version 3.05, under certain combinations of gradient slope, solvent compressibility, and system pressure, results in the GPV staying closed when any solvent reaches a programmed composition of 100%. This issue can result in the loss of pump pressure and prime.

FIX or WORKAROUND

Update firmware to v3.06.

ADDITIONAL INFORMATION

For example, the gradient line at 4.10 min did not function; that is, the gradient valve closed line A but failed to open line B.

This fix is now part of firmware 3.06 and is deployed on most of the newer systems. Another workaround was to leave the line at 4.0 min at 100% and put a second line in at 4.1 min, again with 100% B, which would give a second strike at opening line B.