Valleylab Force FX-8C Service Manual page 135

Situation Possible Cause
Generator is on and Malfunctioning footswitch or
accessory is activated, handswitching instrument
but generator does not
deliver output
Footswitch connected to Monopolar 1
Footswitch receptacle is being used for
instrument connected to Monopolar 2
Instrument receptacle
Footswitch connected to Monopolar 2
Footswitch receptacle is being used for
instrument connected to Monopolar 1/
CEM Instrument receptacle
Power set too low
An alarm condition exists
Blown fuse on Power Supply/RF board
Control board malfunction
High voltage power supply malfunction
(high voltage is not present during
activation)
RF output stage malfunction (high voltage
is present during activation)
Force FX-8C Service Manual
Correcting Malfunctions
Recommended Action
Turn off the generator. Check and correct all accessory
connections.
Turn on the generator. Replace the accessory if it
continues to malfunction.
Connect the footswitch to the Monopolar 2 Footswitch
receptacle.
or
Connect the instrument to the Monopolar 1/CEM
Instrument receptacle.
Connect the footswitch to the Monopolar 1 Footswitch
receptacle.
or
Connect the instrument to the Monopolar 2 Instrument
receptacle.
Increase the power setting.
Check the Cut display for an alarm number. Note the
number and refer to Responding to System Alarms later
in this section.
Check the high voltage power supply fuse (F1) and
replace if necessary. Refer to Fuse Replacement in
Section 7.
If the indicator bar does not illuminate and the tone does
not sound, replace the Control board. Refer to Control
Board Replacement in Section 7.
If high voltage is not present at TP3 on the Power
Supply/RF board, troubleshoot the high voltage power
supply
Troubleshoot the RF output stage as described below:
On the Power Supply/RF board, verify T_ON\ pulses at
U4 during activation.
• If pulses are not present before U4, replace the
Control board. Refer to Control Board Replacement in
Section 7.
• If pulses are present at U4 but not after U4, replace
U4.
Check the power MOSFET at J9 for failure (typically fail
shorted).
Check all output relays to verify that they are toggling
during operation. If they are not, check the relay drivers
(U15 and U16).
Check for shorting of the output tuning inductors (T14
and T15).
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