4-24
• The Forward Converter will oscillate with brief
output bursts when the output current limit
is active. This is generally caused by shorted
MOSFETS on the RF Amplifier.
• At low output current, the PFC will cycle on
and off. This is normal.
• When replacing a MOSFET, check all the gate
drive components.
• Resistance measured between TP7 and TP4
(-HV) when power is off should be greater
than 100K ohms. Resistance measured
between U2P15 (VCC) and TP4 when power
is off should be greater than 100K ohms.
• If either of above is low, Q3 or the associated
protection diodes are suspect. If these are
removed and the measured resistance contin-
ues to be low, U2 is probably failed.
• The forward converter can be disconnected
from the Power Factor Controller for trouble-
shooting the PFC. Do this by removing the
E1-E2 wire. Be sure to note the routing of
the wire through T1 so it can be reconnected
correctly. Incorrect polarity can damage the
Forward Converter.
4.13 Parts Ordering Information
To obtain replacement parts or additional infor-
mation regarding your unit, write or telephone
according to the contact information as listed on
the inside front cover of this manual, or contact
your CONMED distributor. To ensure prompt
service, please provide the following information:
Model Number
Serial Number
Reference Designator and Description of Part
Conmed Part Number (if known)
Quantity Desired
Mailing or Shipping Address
Preferred Shipping Means (if any)
Purchase Order Number (if applicable)
Your Name
If you are returning a unit, obtain a Return
Authorization (R.A.) Number from CONMED
Technical Services. Please mark the R.A. number
on the outside of the carton for prompt service.
4.14 Fault Codes
This section of the manual contains a table of fault
codes. Each numeric fault code is listed along
with a description of the fault, possible causes and
things to check, and corrective actions.
