Poor sensitivity after power outage on TQD - WKB73181

SYMPTOMS

• No peaks after power outage
• Increase of collision energy to 20V brings peaks back, but sensitivity is still diminished 
• All tune readbacks appear correct 
• There is no difference between MS1, MS2, and MSMS, in terms of sensitivity
• Collision guide output voltage readbacks on the T-Wave diagnostics page appears to be 20V when collision energy is set to 0V

ENVIRONMENT

• ACQUITY TQD
• MassLynx

CAUSE

A 20V offset voltage is being applied to the collision ion guide output voltage. Setting Collision Energy to 0V should give a collision ion guide output voltage readback of 0V.

FIX or WORKAROUND

1. Cycle power to the instrument. 
2. If voltage offset is still present after cycling power, replace the ACQUITY TQD T-Wave Generator (700003510).

ADDITIONAL INFORMATION

A collision energy offset can be noted on the "T-Wave Diagnostic" tab in the "Collision Ion Guide Pulse Amp" section. The reading should be opposite polarity of the set collision energy. Example: If collision energy is set to 20V in daughter mode, the average "Collision Ion Guide Pulse Amp" reading should be around -20V. 

The collision energy offset noted above in the "Cause" section may be something higher or lower than 20V (for example, 15V).