Fluke 540B - Page 40

540B
SYMPT
OM
POSSIBLE CAUSE
REMEDY
No
PERCENT INPUT
Low galvo battery. Replace batteries.
meter read ing.
K80 1 not
mak ing contact . Clean th e contacts.
Erratic t ransfer
Poor test lead connect i ons. Check all connecting cables and wiring .
readings or unst a ble
Unstable de or ac source s. Check source stability.
ga lvo.
Low Galvo battery.
Replace batteries.
K801 not making good contact. Clean the contac t s.
Dirty MODE switch contacts . Clean the sw itch contacts.
Galvanometer
Glavanometer circuit out of align - Realign t he galvanometer.
sens i tivity low.
men t.
Input too low
for the r a nge selected. Using the PERCENT INPUT meter in th e
SEARCH MODE, reduce the range setting
until a reading ne a rer 100% is obtained.
GALV
ZERO
Galvanometer circuit out of align - Realign the galvanometer.
inoper ative . ment.
Protection circuit operated.
Recheck the PERCENT INPUT meter and
if an over l oad has occurred, determine
the reason for the over load, correct the
problem and reset the protection circuit.
Fa ils Input Isolation
Input leads to T2 touching the case. Check the l eads to T2 and move th em away
check. (Paragraph
from the case.
4-30)
Defec
tive T2 .
Replace T2.
Protection c ir cuit
Defective diode(s). Check diodes CR303 to 306, CR310 to 303,
fails to calibrate. CR307 and CR314, and Q303 and Q304.
Defective transistor(s).
Figure 4- 6. TROUBLESHOOTING
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4- 8