Zenith H-100 Service Manual page 87

H-207 DISK CONTROLLER TEST
5-171
10-82
CHECK
*Q3 Collector
=
Z
*U 1-16
= 2
MHz
*U7-4
=
L
*U9-19
=
L
*U10-12
= H
*U10-14
= H
*U10-16
= H
,
*U 11-4 =
H
*U 11-6 =
H
*U 11-8 =
H
*U 11-10
=
L
*U 11-12
=
H
*U22-2 =
(H)
*U22-3
=
(H)
*U22-23 =
(H)
*U22-24 = 1
MHz
*U22-27 = P
*U22-34 =
L
*U22-35
=
L
*U22-36 =
H
*U 31-1
= (H)
*U 31-15 =
(H)
*U32-6 =
(H)
*U35-11 =
(p)
*U36-1 = (H)
*U36-19
= (H)
End of test.
IF NOT OKAY, CHECK
U21-8
U13-6
U7-5 (Also press and release
CTR/RESET. U7-4 should
remain low for about 18 seconds.
If not, then replace U15.)
U30 or the data bus is defective.
U10 or U22 is defective.
U10 or U22 is defective.
U10 or U22 is defective.
U11-3
U11-5
U11-9
U11-11
U11-13
U21-11
U21-3
U15-7
U13-8
U16-9
U9 is defective.
U9 is defective.
U9 is de fective.
U27-8
U17-14
U32-5
U28-4
U27-8
U27-8