7
Control Board Preparation
If the firmware on the Control board must be upgraded, do so now. Follow all instructions supplied
with the upgrade, but leave the cover off when finished.
Make sure the firmware installation is complete
and that the K2 is working correctly before continuing.
Turn off the K2. If the internal battery (KBT2) is installed, put its switch in the OFF position.
Remove the K2's top cover (six screws). Disconnect cables for the options, speaker, and freq. counter.
Remove the two screws that hold the Control board to the Front Panel board. Extract the Control
board using the long-handled Allen wrench as explained on page 40 of the K2 Owner's Manual (fig. 6-11).
Place the Control board on a clean work surface, with the top side up (the side with most parts).
Check the revision of your Control board, which appears at the bottom right. If your Control board is
revision A (or earlier, i.e. XA, XB, XC), you'll find that the component outlines for the KAF2 connectors
(J1 and J2), as well as the audio filter module itself, appear on the
bottom
side of the board.
DO NOT
install J1 and J2 on the bottom side of the Control board. The KAF2 module and associated
connectors will be installed on the top side.
i
When removing R18 and R19 from the Control board in the following steps, be very careful not to
damage the pads or traces. You can use solder wick or a vacuum desoldering tool. Another method is to
clip the leads of the resistors right at the body, then remove the leads one at a time. Use long-nose pliers to
hold the lead, then heat the joint until the lead slides out with very little pulling force. If R18 and R19 are
jumpers rather than resistors, removal will be easier, but it must still be done carefully.
Locate R18 and R19 (resistors or jumper), located near the right end of the 36-pin connector, P2.
De-solder and remove them from the Control board.
Observe the precautions above.
Use solder wick or a vacuum desoldering tool to remove residual solder from the resistor holes.
Do
not overheat the pads
. The holes must be completely clean to allow installation of the KAF2 connectors.
Install the 5-pin and 3-pin female connectors, J1 and J2, on the top side of the Control board. (As
mentioned above, if you have an older Control board, the outlines are on the bottom. You'll still use the
same holes.) Solder just one pin of each connector.
If either J1 or J2 is not seated flat against the board, reheat the appropriate pin and adjust the connector
as needed. Once both connectors are straight and seated correctly, solder all remaining pins.
There are several electrolytic capacitors on the top side of the Control board in the area where the
KAF2 will be installed. (See illustration on next page.) Straighten C28, C29, C32, and C33 to avoid
possible interference with the KAF2. Make sure that all other components in this general area have short
leads and are seated correctly.
Plug the Control board into the RF board. Make sure that all three connectors on the Control board are
properly mated with their respective RF board connectors.
Содержание KAF2
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