Zenith H-100 - Page 17

U187-2
=
L
(MB1) U186-18
U187-3
=
p
(MB1) Restore
U186-4
and U186-5
and go
to CLOCK CIRCUITS
TESTS.
U187-4
=
H
(MB1) U203-11
U187-5
=
L
(MB1 )
U187-2_ U187-3_
U187-4
U187-9
=
H
(MB1)
U187-11_ U187-12
U187-11
=
P
(MB1)
Restore U186-4
and U186-5
and
go
to CLOCK CIRCUITS
TESTS.
U187-12
=
H
(MB1 )
U186-13
U203-11
=
H
(MB1)
U203-13_
U203-12
U203-12
=
H
(MB1)
U186-16
U203-13
=
L
(MB1)
Restore U186-4
and U186-5
and
go
to CLOCK CIRCUITS
TESTS.
U210-38
=
H
(MB1)
U210-39
U210-39
=
H
(MB1)
U181-9
U211-30
=
L
(MB1)
U211-31
U211-31
=
L
(MB1)
U187-5
U215-2
=
H
(MB1 )
Restore
U186-4
and
U186-5
and go
to CLOCK CIRCUITS
TESTS.
U215-3
= L
(MB1)
U215-2
======================================================================
SWAP TEST #3
3-143
1. Restore pin 4 of U186; leave pin 5 lifted.
2. Jumper U186-5 to ground.
3. Turn on the H/Z-100.
4. Connect a jumper wire from ground to pin 74 of the
S-100 bus (HOLD·).
5. Perform the following tests:
..
CHECK
·U180-9 = H
(MB 1)
IF NOT OKAY_ CHECK
U180-10
10-82
Go to Swap Test #4.