4-20
M1 5 Vdc and
- 1 5 V dc power supply
No
Voltages at points
+ 1 5 & -1 5 on Mai nboard
Yes
Troubleshoot Mainboard
T urn off instrument and
disc 15 & - 1 5
power suppl y leads from
Mai nboard . Turn on
instrument and measure
+ 1 5 V dc and - 1 5 V d c
at these l eads .
Yes
T urn off i nstrumen! and
reconnect l eads to Main-
baa rd . Turn on instrument
and al low 1 0 minutes warm
up. Touch each Op-Amp
No
and determi ne wh ich one is
running hotter than the others .
Replace hot Op-Amp as per
Section 4-6 .
2nd Level Troubleshoating Tree
T
roub leshoot
Power Supply
Board
Summary of Contents for 452
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