15
Insert U1 into its socket, with the notched or dimpled end of the IC aligned with the notched end of the
PC board outline. Make sure
all
pins of U1 are lined up with the socket. (Figure 10 shows an 8-pin IC; U1
is similar but has 18 pins.) Press U1 down into the socket as far as it will go.
Figure 10
Note:
IC pins are counted by going around the IC counter-clockwise from pin 1.
Examine U1 closely. If any pins are bent, remove the IC and straighten them. (To remove U1 from its
socket, pry it up gently on each end using a small flat-blade screwdriver.)
Examine both sides of the Filter board closely for cold solder joints, solder bridges, and unsoldered
components.
The resistance measurements listed below will help you identify problems with relays and a few
important signals on the Filter board. A DMM (digital multimeter) should be used rather than an analog
VOM (volt-ohm meter). To make the measurements, touch your DMM's (+) and (-) leads to the indicated
points. The Filter board schematic (pages 23 and 24) may help you troubleshoot any incorrect readings.
Note:
The symbol
>
means
greater than
, and
<
means
less than
. Your DMM may indicate infinite
resistance (all digits flashing, or a flashing "1") for readings that are listed as greater than some value.
Test Points (+, -)
Resistance
Test Points (+, -)
Resistance
P1 pin 1, P1 pin 2
< 5 ohms
U1 pin 1, U1 pin 2
360-440 ohms
P1 pin 3, P1 pin 4
> 100 k
U1 pin 6, U1 pin 7
360-440 ohms
P2 pin 2, P2 pin 4
> 10 k
U1 pin 8, U1 pin 9
360-440 ohms
P3 pin 1, P3 pin 3
> 100 k
U1 pin 9, U1 pin 18
360-440 ohms
P3 pin 8, P3 pin 6
> 100 k
U1 pin 17, U1 pin 18
360-440 ohms
U1 pin 13, P2 pin 6
90-110 ohms
If your K1 is already fully assembled, go on to Initial Test (next page).
Otherwise, turn to section 5
of the K1 Owner's Manual (page 17) and continue with K1 Front Panel and RF Board assembly. You'll
come back to this manual later to align the 4-band Filter board.