Xevo TQD MS1 sensitivity is too low to see MS2 - WKB94336

SYMPTOMS

• Xevo TQD MS1 sensitivity is too low to see MS2
• Peak sensitivity suddenly decreases in MRM measurement; a cold reset of MS temporarily improves the situation

ENVIRONMENT

• Xevo TQD
• MassLynx

CAUSE

Defective RF2 generator or defective personality board

FIX or WORKAROUND

1. Check the rectified voltage and make a voltage division.
2. If the rectified voltage of MS2 is 0 V even when confirming with Align mode: Change the MS number to 0-2000 with Span 0 in Normal mode. If the rectified voltage of MS2 is still 0 V, there is no output from the RF2 generator and it needs to be replaced.
3. If the MS2 rectified voltage is normal (-3.37 V and so on) when confirming with Align mode: Change the MS number to 0-2000 with Span 0 in Normal mode. If the rectified voltage of MS2 is still 0 V, the MS program on the personality board is not working and the board needs to be replaced.

ADDITIONAL INFORMATION

Normally, MS2 rectified voltage is -3.37 in Align mode, and it varies when MS number is 0-2000 with Span 0 in Normal mode (-4.91 for 1000 mass, -9.85 for 2000 mass).