Agilent Technologies 7820A

Agilent 7820 GC Service
7
Motor Harness & AC Control Assembly ......... 184
Inlet/Detector heater harness ............... 187
Aux Heater/Valve Box Harness ................ 188
Communications Harness ...................... 188
7820 GC/MS Second Inlet Upgrade Harness..... 191
Keyboard display cable ...................... 192
Display Cable Assembly ...................... 192
9 Mainframe 193
Mainframe overview .......................... 194
Covers and Fans ............................. 194
Removing and replacing the covers ........ 194
Replacing the oven bezel ................. 196
Replacing the inlet cooling fan .......... 196
Replacing the EPC cooling fan ............ 197
Replacing the oven door ..................... 199
Oven temperature control .................... 200
Oven temperature troubleshooting ............ 200
Measuring inlet and detector heater and PRT
resistance .................................. 201
Testing resistance of the oven heater coil . 204
Replacing the oven shroud, oven fan, and oven fan
motor ....................................... 205
Replacing the oven flapper assembly ......... 208
Replacing Components Inside the Electronics Panel
............................................ 209
Accessing the analog and power board ..... 209
Replacing the ALS board .................. 209
Replacing the fuse on the ALS controller board
.......................................... 212
Removing the valve bracket ............... 214