SIGNATURE 2.0 (serv.man8) - Harman Kardon Audio Technical Bulletin (repair manual). Page 2

harman/kardon Incorporated

250 Crossways Park Dr.  Woodbury, New York  11797  (516) 496-3400

2

 

2.0

Software (IC U305) Replacement Instructions

Before replacing the software in the SIGNATURE 2.0 Processor, confirm the Software revision in the unit. To
check, plug the unit in and turn it ON.  The display will  read “Ver __.__”.  Make sure the version you are
replacing is a higher number than what’s on the display.

CAUTION: IC U305 EPROM IS AN ELECTROSTATICALLY SENSITIVE DEVICE AND CAN BE DAMAGED
BY CARELESS HANDLING; YOU MUST FOLLOW PROPER STATIC CONTROL PROCEDURES TO
PREVENT DAMAGE TO THE DEVICE.

1.  Confirm the unit is unplugged and OFF.
2.  Remove the 7 top cover screws. There are 2 on each side and 3 on the upper portion of the back panel.
3.  Remove the top cover; slide it towards the back of the unit about an inch and lift it off from the back first.
4.  Locate the video board directly behind the video jacks. Unplug the ribbon cable marked “CONTROL” on the

circuit board under the ribbon.  Unplug the green power supply cable marked “PWR”; apply only upward
force to remove it.

5.  Locate and remove the (4) screws and (1) nut holding the video board on. Two screws are located between

the “COMPOSITE VIDEO” RCA jacks on the back panel.  Two screws, with washers, are located on either
lower side of the “S VIDEO” jacks on the back panel. The (1) nut is located on the inside corner of the
printed circuit board next to capacitor C504.

6.  Remove the video board by lifting the edge of the circuit board that has the connectors on it (CONTROL

and PWR) up and out of the way of the power supply capacitors before complete removal.

7.  The software IC (U305) should be visible at this point.  Find it on the CPU circuit board under the video

board, plugged into a 32 pin IC socket marked U305. You may need to move the 10 conductor ribbon cable
aside to read the locator number; there is also a label on the IC stating the software version. (On one side
of the IC there is a ribbon connector, on the other side of the IC is another device - MS6264L).

8.  Apply a “L” shaped pick or jewelers flat blade screwdriver between the IC (U305) and socket at the notched

end. Pry the end of the IC up enough to grab it and carefully lift straight up without further bending the pins
while you complete the extraction.

9.  Test fit the new IC (h/k part# A003-0020-4). The legs usually need to be bent inward. Do this by placing

one side of the IC legs against the edge of a table to bend all of them at the same time. Do this on both
sides just enough for the IC to fit properly into the socket.

10. Position the IC so the notch faces towards the transformers. Line up the legs into the socket and press

down hard enough to seat the IC into the socket. Look at the legs on both sides of the IC and make sure
there are not bent or misaligned.

11. Reinstall the video board in the same manner it was removed as in step 5, and reinstall the screws in their

respective locations.

12. Plug the ribbon cable into the connector marked “CONTROL” and the green power cable into the connector

marked “PWR”.

13. Replace the top cover in the same manner it was removed  in step 2, and reinstall the 7 screws. Tighten

the rear panel screws first.

14. You must do a reset for the new software to be enabled.  Make sure the On/Off button is in the OFF

position. Plug the unit into an AC outlet. While pressing the SOURCE and MUTE buttons down at the same
time, turn the On/Off button to the ON position. At this moment, the lower line of the display must read
“Initialized”.  You may then release the buttons.