Lincoln Electric IDEALARC DC-600 Service Manual page 98

F-54
REMOVAL AND REPLACEMENT PROCEDURE (continued)
NOTE: If it is necessary to remove and replace only
one or two individual SCRs and they are easy
to work on, use these procedures.
1. Disconnect main AC input power supply to the
machine.
2. Identify and label the following :
a. The transformer secondary lead (heavy alu-
minum conductor) connected to the anode of
the SCR heat sink for each assembly to be
removed. See Figure F.19.
b. The snubber leads for each SCR heat sink to
be removed. See Figure F.19.
TROUBLESHOOTING AND REPAIR
SCR / SCR OUTPUT BRIDGE
FIGURE F.19 - Individual Heat Sink Removal
IDEALARC
3. Disconnect the transformer secondary lead to the
anode of the heat sink assembly using 1/2" socket
wrench and 1/2" open end wrench.
4. Disconnect the gate lead to the SCR.
a. If the gate lead is cut, it will have to be re-sol-
dered when the replacement SCR is installed.
b. If a new snubber board is used, install proper-
ly.
® DC-600
F-54