Fluke 43B - Page 151

43B Service Manual
9-10
R488 = 0 Ohm for Intel 16M ROM
ST8557-1 000121
R485 - R486 for electronic, R489 for visual mainboard version detection.
R498 R497
128x8 open 0 Ohm 256x8 open 0 Ohm 512x8 0 Ohm open
C476 100n
1 2
1
3
R481
R482
+VD
5 4
1
R483
0E
OPTION
511E
V471
BAS85
51K1
C470
470P
D480
74LVC32
D480
74LVC32
6
Delay circuit for PCB version 3
ROMWRITE
Direct connection for PCB version < 3
ST8557-1.WMF
Figure 9-4. Circuit Diagram 4, Digital Circuit