Lincoln Electric PRECISION TIG 375 IM909 Operator's Manual page 36

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Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
No hi-freq
Hi-freq intensity too weak
Hi-freq on continuously in DC Tig
Hi-freq shuts off after starting in AC
Tig
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local
Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
TROUBLESHOOTING
POSSIBLE
CAUSE
HI-FREQ PROBLEMS
1. Circuit breaker CB1 open
2. Bad connection at P12 of Control
PC board
3. Spark gaps shorted
4. Faulty Control PC board
1. Dirty spark gap or improper gap
setting
2. Faulty Arc Starter assembly
1. Bad connection at P11 of Control
PC board
2. Micro-switch S2A is not engaged &
disengaged properly when switch-
ing between DC & AC polarity.
(S2A locates on the Polarity
switch)
3. Faulty Control PC board
1. Micro-switch S2A is not engaged &
disengaged properly when switch-
ing between DC & AC polarity.
(S2A locates on the Polarity
switch)
CAUTION
PRECISION TIG 375
RECOMMENDED
COURSE OF ACTION
If all recommended possible areas
of misadjustment have
checked and the problem persists,
Contact your local
Authorized Field Service Facility.
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been
Lincoln