Philips PM2521 Service Manual page 177

5
10.2. Free-run test.
Settings signature analyser
Setting Edge Testpoint Signalname
TT
start "U.
(neg)
D1905
pin 12
A10
IT
IT
stop d" (pos)
D1905 pin 12 A10
!1
clock (pos)
TP15
ALE
ground
—
TP1
logic 0
5V
L
NO
TE:
1.
Remove D 1909 and
D
1920 (ROMs).
2. Signals with
a
*
seem
to
be
logic
0 or
logic
1
but
still
show
activity,
(blinking led.)
3.
Reference
logic
0 =
0000
logic
1
=
8P54
7AV1 AO
GND vcc
AJ
®
7
A2
6
A3
H10F
5
A4
^
I5.H]
53HH
1
3A9A
4
AS
"lP2l
10F6
mnfl
3
A6
"im
CAAt
2
A7 A218
1
1
0751
52BH [P20)
EID^'
17
0001
Iral"
IS
8P54
VPP
-
OE CE
1
7A33
AO
GND VCC
*,
=
A2
'
I
HH53 A3®
H10F
AA®
A6
^
1
0108
*6®
FB1C
*7®
1
1
[P20l
8r?H
I31l"
1
0001
E2E"
19
n
VPP
OE CE