Panasonic KX-HCM110A Service Manual page 28

Caution:
See the Figures for the position in the attachment of the Main PCB Sheet
and the Sheet.
Press the Flat Surface shown in the Figure, then press the whole sheet
securely to avoid peeling.
The Sheet should not cover the connector in FIG. 2.
9.2. CAUTIONS FOR FFC CABLE ATTACHMENT
Process the FFC Cable to insert to the connectors of the I/O Board and the Main Board.
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