HP 8642A Operating Manual page 360

S e r v i c e
Model 8 6 4 2 A / B
N o t e s :
1. Each module in the HP 6642 has a nine digit module identification code. The first four digits comprise the
module configuration code. When servicing a module, note any changes that apply specifically to its module
configuration code.
2. All circuit boards are manufactured using a hot air leveled process. These boards require extra care Mhen
replacing components. Refer to General Service Information, paragraph B-3.
3. W2 and W3 are 8 contact blue post jumpers. They connect one row of J2 to the single row of Jl for normal
operation. To disconnect data bus. move jumpers over to connect one row of J2 to its other row. This other
row is grounded.
A3
S1
COMPONENT SIDE
TOP V I E W
10 9 8 7 6
r-1 Cl
0J.
r—i C3 i — i
O I O
'—' C2 '—'
1 2 3
S c h e m a t i c General Information
8 F - 1 0 4