We were almost finished with a run when filament 1 blew and I had to change to filament 2. The DFTPP would no longer pass. I tried the standard spectra autotune and it failed. So I did a target tune to try to get DFTPP to pass. I am not getting any m/z 441. I have tried raising and lowering the abundance for target tuning as well as adjusting the dynamic lens ramp. Nothing seems to be working. Any suggestions will be greatly appreciated so I can get this run finished before cleaning the source. Thanks.