Service Bulletin no. 1062 (23 January 1998)
When the transceiver is turned off, there is a momentary increase
in back-up battery current drain. In addition, if a personal
computer is connected to the transceiver, excessive back-up battery
current drain can occur when the transceiver is turned off. The
following circuit changes will eliminate the increased current
Caution: This modification requires soldering equipment
rated for CMOS type circuits. It also requires familiarity with
surface mount soldering techniques. If you do not have the proper
equipment or knowledge do not attempt this modification yourself.
Seek qualified assistance.
Qty Description New Part No.
2 10 Kohm resistor RK73FB2A103J
1 Diode 1SS355 *
1 470 ohm resistor RK73FB2A471J **
* You can substitute an MA110 diode in place of the 1SS355
** The 470 ohm resistor is only required for S/N 903xxxxx
- Disconnect the power cable and remove the covers of the
Access the foil side of control board
- Remove the solder resist from three foil locations.
- Cut one foil trace. Do not cut too deep.
- Add the two 10 Kohm resistors and one diode.
- On the component side of the Control board, replace R36 with a
470 ohm resistor if a 10 Kohm resistor is installed (This must be
done from S/N 903xxxxx and higher).
- Remove the lithium battery and measure it's voltage. If it
measure 2.8 V or less, you need to replace the battery with a new
one (part number W09-0873-05).
Battery installation procedure:
Perform the following steps when installing the original or
replacement lithium battery.
- Once the battery is removed from it's socket, wait 20 seconds
or more before going to the next step.
- Connect a power supply to the transceiver. The transceiver
should turn on by itself.
- Install the original or replacement battery.
- Turn off the transceiver from the front panel power
- Reset the transceiver by holding A=B key depressed while
turning on the transceiver from the front panel power switch.
Units with a number 3 stamp on the outside box were already
modified at the factory.
Time required to make this changes is 1 hour.