Heathkit IO-4550 - Page 42

LOCATING THE PROBLEM
This test will help you isolate the problem to a particular
circuit. Then, with the aid of the remaining charts, you can
locate and correct the problem.
1. Connect the line cord plug to an AC outlet.
2. Turn on the Oscilloscope.
3. Set the front panel controls as follows before each
test:
INTENSITY
FOCUS
Y1:
INPUT switch
VOLTS/CM
VARIABLE
POSITION
Center of rotation
Center of rotation
GND
50 mV
Fully clockwise (CAL)
Center of rotation
Y2: .
INPUT switch GND
VOLTS/CM 50 mV
VARIABLE Fully clockwise (CAL)
POSITION Fully counterclockwise (OFF)
OTHER:
TRIG MODE AC
HOR IZ POS Center of rotation
TRIG Y1,+
LEVEL Center of rotation, and 0
pushed in (AUTO) P
TIME/CM EXT
VARIABLE Fully clockwise (CAL) and
pushed in
Perform the power supply tests (#1 through #5, in
the “Illustration Booklet”) to verify the operation of
the power supplies before proceeding. The power
supplies must operate properly before you attempt
any further troubleshooting.
Perform the steps as directed in the “Trouble Locator
Chart” (in the “Illustration Booklet’’).