Heathkit IO-4550 - Page 38

IN CASE OF DIFFICULTY
The troubleshooting information for your Oscilloscope is
presented as a general troublehooting table and in a series of
test charts. If you know that a problem exists in a particular
circuit, proceed to the test chart that covers that circuit.
However, if your Oscilloscope does not operate for an
unknown reason, proceed to ‘General Troubleshooting”
and/or the section entitled “Locating the Problem.” Read
the following paragraphs carefully before you begin
troubleshooting. You should also read the “Circuit
Description.”
TROUBLESHOOTING PRECAUTIONS AND NOTES
WARNING: The full AC line voltage and high voltage DC is
present at several points in the Oscilloscope. Be careful to
avoid personal shock when you work on the Oscilloscope.
Be cautious when you test transistors and integrated © When you make repairs to the Oscilloscope make sure
circuits. Although they have almost unlimited life you eliminate the cause as well as the effect of the
when used properly, they are much more vulnerable to trouble. If, for example, you should find a damaged
damage from excessive voltage and current than other resistor, be sure you find out what caused the resistor
circuit components. to become damaged. If the cause is not eliminated, the
replacement resistor may also become damaged when
Be careful so you do not short any terminals to the Oscilloscope is put back into operation.
ground when you make voltage measurements. If the
probe should slip, aor example, and short out a bias or 5 Refer to the “X-Ray Views” and the ‘Schematic
voltage ‘supply ‘palnt, St may. Gamage:one. of more Diagram” to locate the various components.
components.
e
Do
not
remove
any
components
while
the
@
Use
a
high
impedance
voltmeter
to
make
the
specified
OC
Refer to Figure 23 (in the “Illustration Booklet’’).
Oscilloscope
is
turned
on.
measurements in this section.
is