CDX-GT56UI - Sony Car Audio Service Manual (repair manual). Page 6

• 

Distinguish method by part No. printed on the KEY board

• 

Distinguish method by LCD driver IC (IC901) on the KEY 
board

ABOUT  CHANGE  OF  THE  LCD  DRIVER  IC (IC901)  ON  
THE  KEY  BOARD
In this unit, the LCD driver IC (IC901) on the KEY board has been 
changed in the midway of production.
The following changes are performed by this change.

• 

Change of the KEY board (suffi x-21/-22) 
(Refer to supplement-1)

• 

Change of part No. of the FRONT PANEL OVERALL ASSY 
(Refer to page 40)

• 

Change of part No. of the MAIN board 
(Refer to page 39 and 43)

• 

Change of part for Ref No. IC501 on the MAIN board 
(Refer to page 45)

Since all the above-mentioned change is synchronous change, 
there is not compatibility of new type/former type in the front 
panel side and main unit side.
Do the work after necessarily referring to following “New/former 
discrimination”.

Note: When the parts of new front panel and the parts of old 

main unit are combined, this unit does not operate nor-
mally.

New/former discrimination:
Three kinds of following distinguish methods exist.

• 

Distinguish method by serial number printed on the model 
number label

Displayed characters/values are example.

 Serial 

number

CDX-GT56UI

US and 

Canadian 

models

1589832

or smaller

1589833

or lager

US model 
(for CXS-

GT5616F)

1591032

or smaller

1591033

or lager

CDX-GT56UIW

US model

1588217

or smaller

1588218

or lager