Zenith H-100 - Page 15

PROCESSOR SWAP TESTS
SWAP TEST #1
1. Lift pin 5 of U186 (MS1).
2. Jumper U186-5 to ground.
3. Apply power and perform the following steps:
3-141
CHECK
·S100-21
= L
·U180-9
=
L
·U186-3
=
H
·U186-4
= L
(MS1)
(MS1)
(MS1)
(MS1)
IF NOT OKAY, CHECK
U215-3
UlaO-l0
U2l1-30
U17l-5
10-82
Go to Swap Test #2
U17l-l
:: L
(MS1)
U2l0-38
U171-5
= L
(MS1)
U171-1
U180-10
::
L
(MS1)
U186-17
U186-3
=
H
(MS1)
U2ll-30
U186-4
::
L
(MS 1)
U171-5
U186-l6
=
L
(MS 1)
U186-3
U186-17
=
L
(MS1)
U186-4
U186-l8
=
H
(MS1)
U186 is defective.
U187-2
::
H
(MS1)
U186-l8
U187-3
=
p
(MS1)
Restore U186-5 and go to CLOCK
CIRCUITS TESTS.
U187-5
=
H
(MB 1)
U187-2. U187-3
U187-9
= L
(MS 1)
U187-10,
U187-ll,
U187-12
U187-l0
::
H
(MS1)
U203-l1
U187-ll
::
P (MS1)
Restore U186-5 and
go
to CLOCK
CIRCUITS TESTS.
U187-l2
= L
(MS1)
U186-3
U203-1l
::
H
(MS1)
U203-l2, U203-l3
U203-12
::
L
(MS1)
U186-l6
U203-13
:: H
(MS 1)
Restore U186-5 and
go
to CLOCK
CIRCUITS TESTS.