Sony RM-VL900 Operating Instructions (primary manual) Operating Instructions Manual page 49

If none of the above have solved your problems, try the following before contacting
any Customer Support.
To reset the Commander to its factory settings
While holding POWER pressed, press TV/VIDEO and VOL –
until the Commander reacts as follows.
The S (set) indicator and all Component Select buttons light up.
Then the Component buttons turn off one by one, followed by the S
(set) indicator.
When all have turned off, all settings are cleared, and the Commander
returns to its original state (including the preset series of functions on
SYSTEM CONTROL 1 and 3).
For the customers in the U.S.A
Customer Support Information
After you have read through this manual, if you still cannot get the Remote
Commander to work properly, call the Sony Customer Support Helpline
at 1-800-822-2217.
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