
88
Any abnormality suggests an incorrect D/A voltage from the CPU PCB.
V
CP18
= set voltage (V)
A voltage in the range set voltage
±
10% is normal. If abnormal, check the voltage V
CP19
.
If V
CP19
is not in the range +1 to +15V, the IS CTRL PCB is probably defective.
If the V
CP19
voltage is in the normal range but V
CP18
≠
set voltage, the filament wiring is
probably touching another electrode inside the vacuum vessel.
6. Checking the heater circuit
The ion-source heater operates on 24VDC.
No temperature rise when the ion-source temperature is set and the heater should be
operating could be due to a heater discontinuity, short-circuit, disconnected wiring, or
incorrectly installed heater temperature sensor. Follow the procedure below to diagnose
problems with the heater.
Check that the CP2 voltage = +19
±
1V.
If abnormal, replace IS CTRL-A.
Measure the voltage applied to the heater at the feedthrough contacts on the IS CTRL-A
PCB.
HT+ voltage (0 to +24V) Approximately 24V during heating.
HT- Heater - voltage (0V)
The IS CTRL-A PCB is normal if a voltage is applied to HT+.
If the voltage at HT is approximately 0V, a short-circuit has probably occurred in the vacuum
vessel.
Turn off the heater with the tool program. (The sound of the relay on IS CTRL-A operating
should be audible.) Check that the voltage at HT+ is 0V, and then measure the resistance
across HT+ and HT- using the tester resistance mode.
A resistance of 15 to 25
Ω
is normal. Be aware of the polarity when measuring the
resistance; correct measurement is only possible by applying a positive voltage to HT+ and
a negative voltage to HT-. If the polarity is unknown, turn off the instrument power, remove
IS CTRL-A to eliminate the influence of its circuits and measure the resistance directly at the
feedthrough terminals.
Observe the CP1[PWM] waveform with an oscilloscope.
This is normal if an ON/OFF PWM waveform between 19 and 24V is observed, and the HT+
output voltage is approximately proportional to the duty ratio of the PWM waveform (0 to
100%: 0 to 24V).
An abnormal PWM waveform suggests a defective CPU PCB or MAIN CTRL-A PCB.
7. Checking the ion-source temperature measurement circuit
Содержание GCMS-QP2010 Series
Страница 1: ...1 225 00612A Gas Chromatograph Mass Spectrometer GCMS QP2010 Service Manual...
Страница 14: ...14 Do not increase the ion source or interface temperature above the level required for analysis...
Страница 27: ...27...
Страница 71: ...71 Wiring Diagrams 1 Wiring diagram Overall Wiring Diagrams...
Страница 72: ...72 Wiring Diagrams 2 Wiring diagram MAIN POWER ASSY...
Страница 73: ...73 Unit Operation Checks 3 Wiring diagram Details...
Страница 76: ...76 MAIN POWER ASSY Block Diagram Parts inside the broken box are in the MAIN POWER ASSY...
Страница 79: ...79 DC POWER A Block Diagram...
Страница 84: ...84 MAIN CTRL A Block Diagram...
Страница 85: ...85...
Страница 90: ...90 IS CTRL A Block Diagram...
Страница 94: ...94 HV PCB ASSY block diagram 1 UNNCI case of model EI CI 2 NCI case of model NCI...
Страница 98: ...98 IG CTRL A PCB Block Diagram...
Страница 103: ...103 CP6 24V normal range 22 7 to 25 3VDC CP7 24V normal range 22 7 to 25 3VDC CP12 5V normal range 4 8 to 5 3VDC...
Страница 109: ...109 DI CTRL A block diagram...
Страница 145: ...121 5 Remove the IS CTRL A Board Unit Disconnect the two connectors Remove the three screws and the spacer screw...
Страница 150: ...126 Do not remove the 2 screws on the right side Remove the 2 screws on the left side...
Страница 151: ...127 Remove cardboard Move the TW300 left by holding in both hands...
Страница 154: ...130 10 Preparation of new TW300 New TW 300 Removed TW300 Check the name plate Old type New type...
Страница 155: ...131 Remove the cap of outlet Loosen the 3 fixing screws and remove the plate Remove the o ring...
Страница 158: ...134 Hook the right side hooks on the neck of inlet Attach the left side screws and hooks Fasten lightly the 4 screws...
Страница 160: ...136 Remove the cardboard Completion of TMP mounting...
Страница 161: ...137 12 Fix the flange to outlet Place the flange on the outlet Do not forget to place o ring...
Страница 163: ...139 Slide fast the IS CTRL A board down and fix it 4 screws Connect the two connectors...
Страница 164: ...140 14 Place the covers Place the front cover Place the front door...