Zenith H-100 Service Manual page 16

3-142
U210-38
=
L
(MB1)
U210-39
U210-39
=
L
(MS 1)
U187-9
U211-30
=
H
(MS1) U211-31
U211-31
=
H
(MS1)
U187-5
U215-2
=
L
(MS 1) Restore U186-5 and go to CLOCK
CIRCUITS TESTS.
U215-3
=
L (MS 1)
U215-2
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SWAP TEST #2
1. Lift pins 4 and 5 of U186.
2. Jumper U186-4 and U186-5 to 5 volts.
3. Apply power and perform the following tests:
CHECK
.S 100-21
=
H
·U 171-5
=
H
·U180-9
=
L
(MS1)
(MS1)
(MS1)
IF NOT OKAY, CHECK
U215-3
U171-3, U171-2, U171-1
U180-10
Go to Swap Test #3.
U171-1
=
H
U171-2
= H
U171-3
=
p
(MS1)
(MSl )
(MS1)
U210-38
U210-38
Restore U186-4 and U186-5
and go to CLOCK CIRCUITS
TESTS.
U180-10
=
L
(MS1)
U186-3
=
L
(MS 1)
U186-13
=
H
(MS 1)
U186-16
= H
(MS1)
U186-17
=
L (MS 1)
U186-18
=
L (MS1)
U186-17
U211-30
U186-3
U186-3
U186-3
U186 is defective.