Agilent Technologies 7890A Troubleshooting Manual page 5

5 Shutdown Symptoms
6 GC Power On and Communication Symptoms
7 Checking for Leaks
8 Troubleshooting Tasks
Troubleshooting
Flow Never Becomes Ready
Oven Temperature Never Cools Down/Cools Very Slowly
Oven Never Heats Up
Temperature Never Becomes Ready
Cannot Set a Flow or Pressure
A Gas Does Not Reach Setpoint Pressure or Flow
A Gas Exceeds Pressure Setpoint or Flow
The Inlet Pressure or Flow Fluctuates
Cannot Maintain a Pressure as Low as the Setpoint on a Split Inlet
The Measured Column Flow Does Not Equal the Displayed Flow
FID Does Not Ignite 71
FID Ignitor Does Not Glow During Injection Sequence
NPD Adjust Offset Process Fails
FPD Does Not Ignite 74
Column Shutdowns 76
Hydrogen Shutdowns
Thermal Shutdowns 79
GC Does Not Turn On
GC Turns On, Then Stops During Startup (During Self-Test)
PC Cannot Communicate with GC
Leak Check Tips 86
To Check for External Leaks
To Check for GC Leaks
Leaks in Capillary Flow Fittings
To Measure a Column Flow
Measuring FID, TCD, uECD, and FPD column flow
Measuring NPD column flow
To Measure a Split Vent or Septum Purge Flow
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