E8257D/67D, E8663D PSG Signal Generators Service Guide 105TroubleshootingTroubleshooting Unlocks512 A7 Reference UnlockThe instrument’s reference is unlocked. Use the following list to troubleshootthe problem.— If an external reference is connected:1. Measure the external reference signal frequency.2. Measure the external reference signal power level.3. Compare the results from Step 1 and Step 2 against thespecifications found in the E82x7D PSG data sheet.4. Check the connection to the PSG along with the connectors.5. Connect a different external reference source.6. If the error persists, replace the A7 reference board:— If the error occurs when you initially connect or disconnect the externalreference:1. Clear the error queue: press Utility > Error Info > Clear ErrorQueue(s).2. With no changes to the external reference connection, check toensure that the error does not reappear.3. If the error reappears, replace the A7 reference board.— If none of the above apply, replace the A7 reference board.513 1 GHz Out of LockA 513 1 GHz Out of Lock message indicates a failure on the A7 Reference.— Replace the A7 Reference.514 Reference Oven ColdThe Reference Oven Cold Error message indicated the reference has not beenconnected to electrical power for 30 minutes. This message appears when thesignal generator is unplugged or the reference assembly is removed. Themessage is controlled by a timer and should turn off after 30 minutes. This isnot a failure unless the message does not go off after 30 minutes. If itcontinues to be displayed after 30 minutes, replace the A7 Reference.515 10 MHz Signal BadA 515 10 MHz Signal Bad message indicates a problem on the A7 Reference.The error message remains until it is cleared. Ensure that you clear the errormessage prior to each check to properly determine whether the error still persists.
